Primary Sampling Units Research Articles

Knowledge, Attitudes, and Practices on COVID-19 Vaccination among General Adult Population in Malawi: A Countrywide Cross-Sectional Survey.

Vaccination is one of the essential measures in reducing transmission, morbidity, and mortality rates of a disease. However, the COVID-19 vaccination is facing hesitancy across the globe, Malawi included. A population-based cross-sectional study was conducted in Malawi to document knowledge, attitudes, and practices on COVID-19 vaccination. The study targeted the general adult population and employed a multi-stage sampling technique. The Census Enumeration Areas within the 16 selected districts served as a primary sampling unit. Among the total 3068 participants, 1947 (63.6%) were female. About 1039 (34.1%) participants had primary education, while only 169 (5.5%) had college education. A total of 2936 (95.7%) participants knew about the COVID-19 vaccine, and 2063 (68.4%) felt that the COVID-19 vaccine was effective. A total of 1180 (38.7%) got vaccinated. Knowledge of the COVID-19 vaccination was significantly associated with participants' education levels, location, occupation, marital status, household family income, and whether they were suffering from chronic illness or not. Overall, the level of knowledge and attitudes about the COVID-19 vaccination was good. This study has also established that different population groups have statistically different levels of knowledge and attitudes regarding COVID-19 vaccination. This study has also indicated a significant relationship between the rate of vaccination and several factors. Therefore, this calls for stakeholders to continue awareness and group-targeted tailored campaigns so as to increase COVID-19 vaccination.

Key drivers of hysterectomy among women of reproductive age in three states in India: comparative evidence from NFHS-4 and NFHS-5

PurposeAccording to the 4th and 5th rounds of National Family Health Survey (NFHS), there is high prevalence of hysterectomies in the three states of Andhra Pradesh Telangana and Bihar. The three said states have more than double the number of hysterectomies taking place than the national average. Our purpose is to analyse whether these rates are increasing, decreasing or have stabilized and their reasons thereof. Such an analyses will help the policy makers in recommending good clinical practices within their states.Material and methodsWe used data from NFHS-4 (2015-16) and NFHS-5 (2019-2021) rounds. We calculated the differences in predicted probabilities for various factors, performed a Fairlie Decomposition analyses to quantify the positive and negative contributors in the prevalence of hysterectomy across the three states over two time points, and assessed the association of various socio-demographic characteristics to hysterectomy through a multilevel logistic regression model.Results and conclusionThe results show that out of a total of 80,976 eligible respondents from the states under study, 5826 respondents self-reported that they had a hysterectomy done. It was found that older age, living in rural areas, belonging to other backward classes and higher wealth quintile, and higher parity positively contributed to the increased prevalence of hysterectomies in the three states. Higher educational attainment and previous use of family planning methods acted as protective factors. Characteristics at the household level had the highest intra-class correlation value in the prevalence of hysterectomy among women, followed by the Primary Sampling Unit and District levels, indicating high clustering in the prevalence of hysterectomy at the household level in all three states. Heavy menstrual bleeding/pain was the leading cause of hysterectomies in all three states, followed by fibroids/cysts in Andhra Pradesh and Telangana and Uterine disorder/ prolapse in Bihar. Over 80% of hysterectomies took place in the private hospitals.RecommendationsThe study recommends better, more efficient and accountable hysterectomy surveillance to ensure more sustainable woman’s reproductive health services in India. Government should adopt and implement standard regulatory guidelines to prevent provider-driven avoidable hysterectomies. Moreover, we recommend informing primary care professionals about the long-term health effects of hysterectomy and promoting alternate therapies for treating uterine fibroids and heavy bleeding.

Social inequalities in self-reported SARS-CoV-2 infection in Brazilian adults: PNAD COVID-19.

To investigate inequalities related to race/ethnicity and socioeconomic status in self-reported positive diagnosis for COVID-19 in Brazilian adults. Data available from the National Household Sample Survey COVID-19 (PNAD COVID 19) (July/September/November, 2020) were used in this retrospective investigation. The analyses considered the sampling design, primary sampling units, strata and sample weights. Poisson regression with robust variance was used to estimate prevalence ratio (PR) and the 95% confidence interval (95%CI) of the associations. In July, September and November 2020, with regard to the rapid test, indigenous people were 2.45 (95%CI 1.48-4.08), 2.53 (95%CI 1.74-4.41) and 1.23 (95%CI 1.11-1.86) times more likely to report a positive history of SARS-CoV-2 infection, respectively. With regard to the RT-PCR test in November, indigenous people were more likely to test positive for COVID-19 (PR: 1.90; 95%CI 1.07-3.38). It was observed that the indigenous group was 1.86 (95%CI 1.05-3.29) and 2.11 (95%CI 1.12-3.59) times more likely to test positive for COVID-19 in September and November (2020). Income was associated with testing positive for COVID-19: in November, individuals whose income ranged from R$0.00-R$1.044 were more likely (PR: 1.69; 95%CI 1.16-23.06) to test positive using the RT-PCR test; participants whose income was in this range were also more likely to be diagnosed with COVID-19 using blood tests (PR: 1.72; 95%CI 1.43-2.07). The data presented show an association between race/ethnicity and economic status with a positive diagnosis of COVID-19.

Oral rehydration therapy and Zinc treatment among diarrhoeal children in India: Exploration from latest cross-sectional National Family Health Survey.

Diarrhoea is one of the deadliest diseases and causing death among children in India, but no systematic attempt is made to understand it especially its control using oral rehydration salts (ORS). It is well known that use of ORS and Zinc have been effective in containing diarrhoea among children. An attempt is made using large scale national data set in India to understand use of ORS and Zinc to control diarrhoea and their associated factors among diarrhoeal children under five in India. Publicly available most recent cross-sectional National Family Health Survey data in India was used for the study. The multi-stage cluster sampling design was used with 2011 Census of India as a sampling frame. Households were selected using a Systematic Random Sampling design from selected primary sampling units in rural and urban clusters. From the selected households, the eligible children were those who suffered from diarrhoea in the two weeks preceding the survey and were less than 5 years old. Using this criterion, out of 232,920 children in the survey of less than five years, 16,213 sample diarrheal children found to be available for the study. Both descriptive and inferential statistical techniques were used to analyse the data. Across India, 61% and 31% of the children were given ORS and Zinc respectively. However, combined ORS + Zinc treatment was only around 24%. The treatment of ORS, Zinc, and combined ORS + Zinc supplementations were significantly higher among younger children, children of 24-35 age group mothers, children from rich wealth index groups, belong to Hindu religion and general caste compared to their counterparts. The logistic regression results showed that consumption of ORS among diarrhoeal children under five years of age depends upon size of a child at birth. For instance, diarrheal children who were very small size at birth compared to very large at birth, had 39% lower odds of consuming ORS (AOR = 0.61; CI 0.48, 0.78; p<0.001). Another important variable is place of first treatment sought for diarrheal children. That is children who first sought treatment in private hospital compared to government hospital had 52% lower odds of ORS consumption. The logistic regression adjusted AORs are similar with Zinc and ORS + Zinc supplementations. To improve the coverage and management of childhood diarrhoea in India, planning activities should focus not only on distribution, and increasing knowledge of ORS preparation especially for urban slum residents and rural disadvantaged groups through demonstration. There should be also proper focus on providing ongoing pathways to ensure proper supply chains.

High ambient air pollution erodes the benefits of using clean cooking fuel in preventing low birth weight in India

A large fraction of the population in rural India continues to use biomass fuel for cooking and heating. In-utero exposure to the resulting household air pollution (HAP), is known to increase the risk of low birth weight (LBW). Mitigating HAP, by shifting to clean cooking fuel (CCF), is expected to minimize the risk associated with LBW. However, India also has high levels of ambient air pollution (AAP). Whether exposure to AAP modifies the effect of reducing HAP by switching to CCF on LBW is not known. The present study addressed this knowledge gap by analyzing the National Family Health Survey (2019–21) data of the most recent full-term, singleton, live births from rural households born after 2017 (n = 56 000). In-utero exposure to AAP was calculated from satellite-derived ambient fine particulate matter (PM2.5) concentration at the level of the primary sampling unit for the pregnancy duration of the mothers. The moderation by ambient PM2.5 level on the odds of LBW among CCF users was examined by logistic regression analysis with interaction. The adjusted odds ratio (aOR) of LBW was 7% lower among users of CCF. At the lowest Decile (20–37 μg m−3) of ambient PM2.5 exposure, the aOR of LBW among CCF users was 0.83 (95% CI:0.81–0.85). At every 10th percentile increase in ambient PM2.5 exposure (in the range 21–144 μg m−3), aOR increased gradually, reaching the value of 1 at PM2.5 level of 93 μg m−3. Our results, therefore, suggest that the benefit of using CCF during pregnancy may be downgraded by moderate to high ambient PM2.5 exposure.

Validation of a measure to assess decision-making autonomy in family planning services in three low- and middle-income countries: The Family Planning Autonomous Decision-Making scale (FP-ADM).

Integrating measures of respectful care is an important priority in family planning programs, aligned with maternal health efforts. Ensuring women can make autonomous reproductive health decisions is an important indicator of respectful care. While scales have been developed and validated in family planning for dimensions of person-centered care, none focus specifically on decision-making autonomy. The Mothers Autonomy in Decision-Making (MADM) scale measures autonomy in decision-making during maternity care. We adapted the MADM scale to measure autonomy surrounding a woman's decision to use a contraceptive method within the context of contraceptive counselling. This study presents a psychometric validation of the Family Planning Autonomous Decision-Making (FP-ADM) scale using data from Argentina, Ghana, and India. We used cross-sectional data from women in four subnational areas in Argentina (n = 890), Ghana (n = 1,114), and India (n = 1,130). In each area, 20 primary sampling units (PSUs) were randomly selected based on probability proportional to size. Households were randomly selected in Ghana and India. In Argentina, all facilities providing reproductive and maternal health services within selected PSUs were included and women were randomly selected upon exiting the facility. Interviews were conducted with a sample of 360 women per district. In total, 890 women completed the FP-ADM in Argentina, 1,114 in Ghana and 1,130 in India. To measure autonomous decision-making within FP service delivery, we adapted the items of the MADM scale to focus on family planning. To assess the scale's psychometric properties, we first examined the eigenvalues and conducted a parallel analysis to determine the number of factors. We then conducted exploratory factor analysis to determine which items to retain. The resulting factors were then identified based on the corresponding items. Internal consistency reliability was assessed with Cronbach's alpha. We assessed both convergent and divergent construct validity by examining associations with expected outcomes related to the underlying construct. The Eigenvalues and parallel analysis suggested a two-factor solution. The two underlying dimensions of the construct were identified as "Bidirectional Exchange of Information" (Factor 1) and "Empowered Choice" (Factor 2). Cronbach's alpha was calculated for the full scale and each subscale. Results suggested good internal consistency of the scale. There was a strong, significant positive association between whether a woman expressed satisfaction with quality of care received from the healthcare provider and her FP-ADM score in all three countries and a significant negative association between a woman's FP-ADM score and her stated desire to switch contraceptive methods in the future. Our results suggest the FP-ADM is a valid instrument to assess decision-making autonomy in contraceptive counseling and service delivery in diverse low- and middle-income countries. The scale evidenced strong construct, convergent, and divergent validity and high internal consistency reliability. Use of the FP-ADM scale could contribute to improved measurement of person-centered family planning services.

Sociodemographic and health-related differences in undiagnosed hypertension in the health survey for England 2015–2019: a cross-sectional cohort study

Hypertension is a leading cause of morbidity and mortality worldwide, yet a substantial proportion of cases are undiagnosed. Understanding the scale of undiagnosed hypertension and identifying groups most at risk is important to inform approaches to detection. In this cross-sectional cohort study, we used data from the 2015 to 2019 Health Survey for England, an annual, cross-sectional, nationally representative survey. The survey follows a multi-stage stratified probability sampling design, involving a random sample of primary sampling units based on postcode sectors, followed by a random sample of postal addresses within these units. Within each selected household, all adults (aged ≥16 years) and up to four children, were eligible for participation. For the current study, individuals aged 16 years and over who were not pregnant and had valid blood pressure data were included in the analysis. The primary outcome was undiagnosed hypertension, defined by a measured blood pressure of 140/90mmHg or above but no history of diagnosis. Age-adjusted prevalence of undiagnosed hypertension was estimated across sociodemographic and health-related characteristics, including ethnicity, region, rural-urban classification, relationship status, highest educational qualification, National Statistics Socio-Economic Classification (NS-SEC), Body Mass Index (BMI), self-reported general health, and smoking status. To assess the independent association between undiagnosed hypertension and each characteristic, we fitted a logistic regression model adjusted for sociodemographic factors. The sample included 21,476 individuals, of whom 55.8% were female and 89.3% reported a White ethnic background. An estimated 30.7% (95% confidence interval 29.0-32.4) of men with hypertension and 27.6% (26.1-29.1) of women with hypertension were undiagnosed. Younger age, lower BMI, and better self-reported general health were associated with an increased likelihood of hypertension being undiagnosed for men and women. Living in rural areas and in regions outside of London and the East of England were also associated with an increased likelihood of hypertension being undiagnosed for men, as were being married or in a civil partnership and having higher educational qualifications for women. Hypertension is commonly undiagnosed, and some of the groups that are at the lowest risk of hypertension are the most likely to be undiagnosed. Given the high lifetime risk of hypertension and its strong links with morbidity and mortality, our findings suggest a need for greater awareness of the potential for undiagnosed hypertension, including among those typically considered 'low risk'. Further research is needed to assess the impact of extending hypertension screening to lower-risk groups. None.

A community-based cross-sectional study on stressors and gender differences in coping strategies among primary caregivers of cardiovascular disease in the capital city of India, New Delhi

Apart from the impact on mortality rates, CVDs often present as chronic conditions, adding to the stress of caregiving to their caregivers. Males and females cope differently with the stressors in general. In this study, we aim to investigate the gender-based variations in coping strategies among primary caregivers of individuals with CVD.: A sample size of 384 households was selected using systematic random sampling for the study and household was the primary sampling unit. The information was collected regarding the stressors and various coping strategies utilized by primary caregivers to navigate different stressors. Out of the total 384 caregivers, stressors were found in 347 caregivers who were then studied for coping strategies. Among primary caregivers, the proportion of women (58%) was more than men (42%)Planful problem-solving (85.9%) was found to be the most commonly preferred coping strategy among both genders, with no significant association. Among other problem-oriented coping strategies, men caregivers reported using confrontive coping more frequently. While assessing emotion-focused coping strategies, Accepting responsibility (77.5%), Self-controlling (68.9%), Positive appraisal strategy (61.4%) and Distancing (36.3%) were found more likely to be adopted by women. Seeking social support (69%), both problem-focused and emotion-focused coping strategies were found more among women caregivers.By implementing gender-sensitive approaches, we can better support caregivers and help them navigate the challenges of caregiving for individuals with cardiovascular diseases.

The association between higher education attendance and common mental health problems among young people in England: evidence from two population-based cohorts

It is unclear whether young people who attend higher education are at increased risk of common mental disorders, compared with those who do not attend. We aimed to investigate whether higher education attendance was associated with increased symptoms of common mental disorders (depression and anxiety) in young people before, during and after attendance. For this cohort study, we used two cohorts-the Longitudinal Studies of Young People in England (LSYPE1: N=4832, 55·8% [2696 of 4832] students; LSYPE2: n=6128, 50·7% [3104 of 6128] students), beginning in 2004 for LSYPE1 and 2013 for LSYPE2. Both cohorts were designed to be nationally representative, with schools in England as the primary sampling unit. Symptoms of common mental disorders were assessed with the General Health Questionnaire (GHQ-12) before (age 14-17 years for both cohorts), during (age 18-19 years for LSYPE2), and after (age 25 years for LSYPE1) higher education. We assessed differences in GHQ scores using unadjusted and confounder adjusted linear regression. At ages 18-19 years (LSYPE2), mean GHQ-12 scores were 12·0 (SD 6·4) among students and 11·6 (SD 6·8) among non-students (adjusted mean difference 0·36, 95% CI 0·05 to 0·68; p=0·024). In LSYPE1, young people who attended higher education at ages 18-20 years had higher symptoms of common mental disorders at ages 16-17 years than those who did not (0·60, 0·30 to 0·90). However, after higher education (age 25 years for LSYPE1), there was no evidence of a difference-mean GHQ-12 scores were 11·4 (SD 5·5) among those who had attended and 11·7 (SD 6·4) among those who had not attended (-0·25, -0·66 to 0·16; p=0·23). We found evidence that students had more symptoms of common mental disorders than non-students at ages 18-19 years, albeit the effect size was small and there was no evidence of a longer-term difference at the age of 25 years. Department for Education.

Awareness, behavior, and determinants of dietary salt intake in adults: results from the National NCD Monitoring Survey, India

A diet high in sodium contributes to a significant proportion of Disability Adjusted Life Years (DALYs) due to cardiovascular diseases. This paper describes the awareness, behaviour and determinants related to dietary salt intake in an adult population of 18–69 years that were assessed as part of the National NCD Monitoring Survey (NNMS) in India. A sub-sample of 3000 adults selected through simple random sampling from 150 nationally representative Primary Sampling Units (PSUs) was included. Data regarding awareness and behaviour related to dietary salt intake were collected. Urinary sodium excretion in spot urine samples was estimated and used to calculate dietary salt intake. The dietary salt intake’s sociodemographic, behavioural and metabolic determinants were also analysed. Less than one-third of the adults of both genders in all age groups in rural and urban areas were aware that daily high salt intake could affect health. The estimated mean daily salt intake was 8.0 g (8.9 g/day for men and 7.1 g/day for women). The salt intake was significantly higher in men [Adjusted OR = 17.66 (5.24–59.46)], rural areas [Adjusted OR = 6.14 (1.83–20.60)], overweight and obese respondents [Adjusted OR = 17.62 (3.17–98.07)]. The perception of the harmful effects of high salt intake and practices to limit salt intake was low in the study population. The mean daily salt intake was higher than the WHO recommendation of up to 5 g daily. The mean dietary salt intake is high in the Indian population, which calls for planning and implementing control of dietary salt consumption measures.

Coverage evaluation of mass drug administration with triple drug regimen in an evaluation unit in Nagpur district of Maharashtra, India.

Triple drug regimen (IDA; Ivermectin, Diethylcarbamazine, Albendazole) recommended for accelerating elimination of lymphatic filariasis was launched in India in December 2018. Nagpur district in Maharashtra was one of the first five districts where this strategy was introduced. The National Vector Borne Disease Control Programme (NVBDCP) at the district reported ~85.0% treatment coverage in the first round of mass drug administration (MDA) with IDA implemented in EU-2 in Nagpur district in January 2019. As per the national guideline, a coverage evaluation survey was carried out and both quantitative and qualitative data were collected to assess the treatment coverage, the level of community preparation and identify the gaps, if any, for improvement. A Coverage Evaluation Survey (CES) following the WHO recommended protocol was conducted in one of the two evaluation units (EU-2) in Nagpur district in March 2019. Coverage Sample Builder (CSB) V2.9 tool was used to calculate the sample size, select sites and estimate drug coverage. The CSB tool followed a two-stage cluster sampling procedure to select 30 primary sampling units (ward/village as a cluster) and a list of random numbers for selecting households (HHs) in each cluster. The results were analyzed for operational indicators. Stata ver. 14.0 software was used to construct the 95% confidence limits accounting for clustering. A total of 1601 individuals aged 5-85 years of both gender from 328 HHs were surveyed from the 30 randomly selected clusters in EU-2. The mean age was 33.8±17.6 years. Among the surveyed population, 78.0% received the drugs (programme reach) and 66.1% consumed the drugs (survey coverage). Survey coverage was significantly higher in rural (82.6%) than in urban (59.4%) and peri-urban (58.6%) areas (P<0.001). Directly observed treatment (DOT) among the surveyed population was 51.6%. Adverse events were reported among 6.9% respondents who reported to have consumed the drugs. The IDA based MDA strategy could achieve just the required level of treatment coverage (~65%) in EU-2, Nagpur district, which had previously undergone several rounds of DA-MDAs (Diethylcarbamazine, Albendazole). Having achieved an effective treatment coverage of >80% in rural areas, the coverage in urban and peri-urban areas need to be improved in order to attain the impact of IDA-MDA. It is imperative to strengthen drug delivery and community preparation activities along with improved DOT especially in urban and peri-urban areas to achieve the required level of treatment coverage. Addition of ivermectin did not have any additional perceived adverse events.

Scabies prevalence after ivermectin-based mass drug administration for lymphatic filariasis, Samoa 2018-2019.

Scabies is a common skin infestation caused by the Sarcoptes scabei mite. Ivermectin, one of three drugs used in mass drug administration (MDA) for lymphatic filariasis, is also effective for treating scabies. Ivermectin-based MDA was first conducted in Samoa in August 2018, with ivermectin being offered to those aged ≥5 years. Here, we report scabies prevalence in Samoa after MDA. We conducted household surveys 1.5-3.5 months (Survey 1) and 6-8 months (Survey 2) after the 2018 MDA in 35 primary sampling units. We conducted clinical examination for scabies-like rash and used International Alliance for the Control of Scabies classification criteria. We estimated scabies prevalence by age, gender and region. Multivariable logistic regression was used to assess factors associated with prevalence. We surveyed 2868 people (499 households) and 2796 people (544 households) aged 0-75 years in Surveys 1 and 2, respectively. Scabies prevalence increased from 2.4% (95% CI 2.1-2.7%) to 4.4% (95% CI 4.0-4.9%) between surveys. Scabies was associated with younger age (0-4 years: aOR 3.5 [2.9-4.2]; 5-15 years: aOR 1.6 [1.4-1.8] compared to ≥16 years), female gender (aOR 1.2 [95% CI 1.1-1.4]; region (aOR range from 1.4 [1.1-1.7] to 2.5 [2.1-3.1] between regions), large households (aOR 2.6 [2.0-3.4] households ≥13), and not taking MDA in 2018 (aOR 1.3 [95% CI 1.1-1.6]). We found moderate prevalence of scabies in two population-representative surveys conducted within 8 months of the 2018 MDA for lymphatic filariasis. Prevalence appeared to increase between the surveys, and ongoing surveillance is recommended, particularly in young children.

Trajectories of depression and anxiety among older cancer survivors: A group-based trajectory analysis of a nationally representative cohort.

130 Background: Depression and anxiety are common for cancer survivors, especially those aged 65 years or older, which are negatively associated with quality of life and survival. A few studies have described the average population level of longitudinal change in depression and anxiety, but they may not capture the inter-individual variability of the longitudinal trajectory, especially in older cancer survivors. The aims of the current study were to (1) describe the trajectory patterns of depression and anxiety over time among older cancer survivors; (2) examine the socio-demographic and health-related predictors of different subgroups of trajectories. Methods: We used data from the National Health and Aging Trends Study (NHATS), a nationally representative cohort study. The Generalized Anxiety Disorder-2 scale and Patient Health Questionnaire-2 were used to assess levels of depression and anxiety. The group-based trajectory model was used to identify the distinct trajectories of depression and anxiety from 2015 to 2021. Design-based multinomial logistic regression was used to examine the socio-demographic and health-related predictors of different trajectories. All analyses accounted for the complex sample design (stratification and primary sampling units) and survey weights. Results: A total of 1,766 older cancer survivors were included, and the average prevalence of depression and anxiety from 2015 to 2021 was 27.14%. Four trajectories of depression and anxiety were identified: robust (48.9%), deteriorating (24.1%), meliorating (11.0%), and sustained-high (16.1%). Older cancer survivors were at a sustained-high depression and anxiety trajectory if they were older, female, reported poorer health, had a worse cognitive function, and had more difficulty in activities of daily living ( P&lt;0.05). Conclusions: Our findings highlight the heterogeneity and complexity of the depression and anxiety process in older cancer survivors. This study helps identify patients at a high risk of depression and anxiety and develop more individualized strategies to ameliorate the mental health of older cancer survivors.

On using stratified two-stage sampling for large-scale multispecies surveys

Designing a large-scale multispecies survey presents significant challenges due to its multivariate, multiscale, and often multiobjective nature. Because it is impractical to measure or observe all variables of interest at every location in the survey area, spatial sampling is crucial. To ensure a statistically sound survey, free of assumptions, randomization of the selection of spatial sampling units is required.In a large-scale survey, minimizing travel costs requires multistage sampling in which nearby sampling units are grouped within higher-level sampling units. The design may be supplemented by one or more strata systems — possibly nested — that intervene at specific sampling stages. This article focuses on stratified two-stage sampling that balances statistical efficiency and travel cost minimization.As presurvey knowledge, we assume that the spatial distribution of the species of interest is available for the sampled spatial domain, either from a spatial database or a published species distribution atlas. The multispecies nature of the survey sampling plan relies on these data. The primary sampling units are defined by the spatial grid resolution of the distribution data, while the presence data are used to stratify the PSUs to ensure that the sampling effort is concentrated where most species occur.In this article, we formally define the sampling coverage probability of a species distribution when the selection of samples is randomized according to a given probability mass function (i.e., a probability sampling plan or sampling design, in the statistical sense of the term). By maximizing the sampling coverage probability averaged over the species, the stratification and allocation of spatial sampling units concentrate observer effort where most species occur and minimize effort elsewhere.To guide and illustrate our ideas, we present as an example a multispecies waterbird program at the national scale in European France within the framework of probability sampling from finite populations.

Sequential adaptive strategies for sampling rare clustered populations

A new class of sampling strategies is proposed that can be applied to population-based surveys targeting a rare trait that is unevenly spread over an area of interest. Our proposal is characterised by the ability to tailor the data collection to specific features and challenges of the survey at hand. It is based on integrating an adaptive component into a sequential selection, which aims both to intensify the detection of positive cases, upon exploiting the spatial clustering, and to provide a flexible framework to manage logistics and budget constraints. A class of estimators is also proposed to account for the selection bias, that are proved unbiased for the population mean (prevalence) as well as consistent and asymptotically Normal distributed. Unbiased variance estimation is also provided. A ready-to-implement weighting system is developed for estimation purposes. Two special strategies included in the proposed class are presented, that are based on the Poisson sampling and proved more efficient. The selection of primary sampling units is also illustrated for tuberculosis prevalence surveys, which are recommended in many countries and supported by the World Health Organisation as an emblematic example of the need for an improved sampling design. Simulation results are given in the tuberculosis application to illustrate the strengths and weaknesses of the proposed sequential adaptive sampling strategies with respect to traditional cross-sectional non-informative sampling as currently suggested by World Health Organisation guidelines.

Geographical disparities and determinants of infant mortality in Ethiopia: mapping and spatial analysis using EDHS data

BackgroundInfant mortality remains a public health challenge in Ethiopia. Exploring infant mortality will aid in tracking the progress toward achieving sustainable development goals.ObjectiveThe study aimed to explore the geographical variations and associated factors of infant mortality in Ethiopia.MethodA total of 11,023 infants from the 2016 Ethiopian Demographic and Health Survey (EDHS) data were extracted and included in the analysis. EDHS used a two-stage cluster sampling design with a census enumeration area as the primary sampling unit and households as the secondary sampling unit. Arc GIS software was used for spatial analysis using clusters for exploring geographical variations in infant mortality. A binary logistic regression was employed using R software to identify the significant determinants of infant mortality.ResultsThe study revealed that the spatial distribution of infant mortality was non-random in the country. Infants whose mothers not receiving ANC (AOR = 1.45; 95%CI: 1.17, 1.79), not breastfed status (AOR = 3.94; 95%CI: 3.19, 4.81), poor wealth index (AOR = 1.36; 95%CI: 1.04, 1.77), male infants (AOR = 1.59; 95%CI: 1.29, 1.95), birth order of six or above (AOR = 3.11; 95%CI: 2.08, 4.62), small birth size (AOR = 1.27; 95%CI: 1.26, 1.60), birth spacing [(≤ 24 months (AOR = 2.29; 95%CI: 1.79, 2.92), 25–36 months (AOR = 1.16; 95%CI: 1.12, 1.49)], multiple births (AOR = 6.82; 95%CI: 4.76, 10.81), rural residence (AOR = 1.63; 95%CI: 1.05, 2.77) and regions [Afar (AOR = 1.54; 95%CI: 1.01, 2.36), Harari (AOR = 1.56; 95%CI: 1.04, 2.56), and Somali (AOR = 1.52; 95%CI: 1.03, 2.39)] were the determinants of infant death in Ethiopia.ConclusionsThere is a great geographical disparity in infant mortality rates across regions. Afar, Harari, and Somali regions were verified as hot spot areas. ANC usage, breastfed status, wealth index, sex of the infant, birth order, birth size, birth spacing, birth type, residence, and region were the determinants of infant death in Ethiopia. Therefore, appropriate interventions need to be implemented in the hot spots to alleviate the risk factors for infant mortality.

Utilisation of rural primary health centers for outpatient services - a study based on Rajasthan, India

IntroductionOutpatient services are crucial for strengthening primary healthcare and reducing out-of-pocket spending, which has been one of the major causes of impoverishment. So it is also critical to comprehend the people’s preferences in accessing primary healthcare facilities, as government primary healthcare facilities in India are underutilized. The current paper explores the factors that construct the individual’s decision to seek outpatient care in primary healthcare facilities in India’s largest state Rajasthan.MethodsIt was a cross-sectional survey conducted in 72 primary sample units of 24 primary health centers in 11 districts of Rajasthan, India, from November 2019 to January 2020. The study selected 368 households through purposive sampling. Out of 368 households, 460 people reported any illness and 326 reported outpatient visit to any health facility in the last 30 days from the date of the survey.AnalysisThe focus was on analyzing the data in the context of public and private health facilities to understand the factors influencing people’s choice to access outpatient services. The principal component analysis is used to understand the relationship between facility preparedness and OPD uptake. Also, multivariate logistic regression is applied to assess the significant predictors in using primary health facility services.ResultExcept for the 29% of patients who received no care, the proportion of patients attended public health facilities was 35%, and the rest were utilizing private health facilities. Those who sought care at PHCs were mostly over 45 years age, non-literate, and from the lowest wealth quintile. Logistic regression suggests that people belong to upper wealth quintile (OR = 0.298; 95% 0.118–0.753) are less likely to visit PHCs for treatment. Also, increase in distance of PHC (OR = 0.203; 95% CI 0.076–0.539) reduces the likelihood of their visit outpatient care. People are 9.7 times (OR = 9.740; 95% CI 2.856–33.217) more likely to visit a PHCs that are better equipped in terms of human resources, equipment, and medicine.ConclusionThe uptake of PHCs depends on several factors, which should be considered to ensure that all segments of society have equitable access to them. Through improved accessibility and quality of service, PHCs can be made more appealing to the larger population.

Adaptation of Statistics Canada and Eurostat methodologies for variance estimation of changes of the main labour force indicators in Iran

The changing values of the indicators obtained from national labour force surveys provide analysts and planners with valuable information on the fluctuations of the labour market of the country. Labour force surveys in many countries follow the standards established by the International Labour Organization, and, as a result, tend to be similar in various respects. Given these similarities, the procedures used by the statistical organizations of Canada and the European Union are examined in this paper for the development of variance estimates of changes of the labour force indicators in Iran. While the survey in Iran and those in the countries under study have many similarities, they also differ in certain respects, namely, in terms of the periodicity of the survey, the rotation pattern as well as the unit of rotation, and the possible existence of non-response among the primary sampling units. Here, first, the methodologies of Statistics Canada and Eurostat are modified and adapted to the particularities of the labour force survey in Iran. Then, the results are compared. Among the four methods examined, the bootstrap methodology of Statistics Canada, after some modifications and adaptations, is found to be especially suitable for application in the labour force survey of Iran and, perhaps, in other counties with similar conditions. The proposed methodology can, particularly well, take into account the impact of the various steps of weight calculations on the variance estimates of change of the main labour force indicators.

Proportions of and trends in exposure to pro-tobacco and anti-tobacco advertisements among young adolescents aged 12–16 years in 142 countries and territories, 1999–2018: an analysis of repeated cross-sectional surveys

The proportions and trends in exposure to pro-tobacco and anti-tobacco advertisements among young people remain unknown globally. We determined recent (2010-18) proportions of exposure to pro-tobacco and anti-tobacco advertisements among young adolescents and their secular trends from 1999 to 2018. In this analysis of repeated cross-sectional surveys, we used the most recent data from 142 countries and territories (hereafter referred to as countries) collected between Jan 1, 2010, and Dec 31, 2018, comprising 710 191 participants, to assess the proportions of exposure to pro-tobacco and anti-tobacco advertisements among young adolescents aged 12-16 years. Data from 120 countries that had performed two or more Global Youth Tobacco Surveys between Jan 1, 1999, and Dec 31, 2018, comprising 1 482 031 participants, were used to assess trends in the proportions of exposure to pro-tobacco and anti-tobacco advertisements over time. A χ2 test analysis was used for proportion comparisons between subgroups. Exposure to pro-tobacco and anti-tobacco advertisements were calculated as proportions using sampling weights, strata, and primary sampling units. The most recent global proportion of past 30-day exposure to tobacco advertisements among young adolescents was 433 585 (64·6%) of 710 191 (95% CI 63·5-65·7; all final percentages were weighted) for messages on electronic media, 206 766 (33·1%) of 710 191 (31·9-34·4) for exposure at the point of sale, and 63 385 (10·2%) of 710 191 (9·7-10·6) for owning something with a tobacco brand logo. The most recent global proportion of exposure to anti-tobacco advertisements was 431 862 (63·6%) of 710 191 (62·3-64·9) for messages on electronic media and 227 658 (34·1%) of 710 191 (32·8-35·3) for exposure to gathering activities. The majority of included countries showed a decreasing trend in exposure to tobacco advertisements (111 [93%] of 120) and anti-tobacco advertisements (110 [92%] of 120) between 1999 and 2018. Among young adolescents, exposure to tobacco advertisements remains high, and exposure to anti-tobacco advertisements is not high enough. The proportion of young adolescents exposed to pro-tobacco and anti-tobacco advertisements had decreased over time in the majority of included countries. These findings underscore the importance of strict implementation of regulation on tobacco control including strengthening anti-tobacco marketing and prohibiting tobacco marketing. Youth Team of Humanistic and Social Science of Shandong University. For the Chinese translation of the abstract see Supplementary Materials section.

Patterns in the Prevalence of Unvaccinated Children Across 36 States and Union Territories in India, 1993-2021

Children who do not receive any routine vaccinations (ie, who have 0-dose status) are at elevated risk of death, morbidity, and socioeconomic vulnerabilities that limit their development over the life course. India has the world's highest number of children with 0-dose status; analysis of national and subnational patterns is the first important step to addressing this problem. To examine the patterns among children with 0-dose immunization status across all 36 states and union territories (UTs) in India over 29 years, from 1993 to 2021, and to elucidate the relative share of multiple geographic regions in the total geographic variation in 0-dose immunization. This repeated cross-sectional study analyzed all 5 rounds of India's National Family Health Survey (1992-1993, 1998-1999, 2005-2006, 2015-2016, and 2019-2021) to compare the prevalence of children with 0-dose status across time-space and geographic regions. The Integrated Public Use of Microdata Series was used to construct comparable geographic boundaries for states and UTs across surveys. The study included a total of 125 619 live children aged 12 to 23 months who were born to participating women. The outcome was a binary indicator of children's 0-dose vaccination status, coded as children aged 12 to 23 months at the time of the survey who had not received the first dose of the diphtheria-tetanus-pertussis-containing vaccine. The significance of each geographic unit was computed using the variance partition coefficient (VPC). Among 125 619 children, the national prevalence of those with 0-dose status in India decreased from 33.4% (95% CI, 32.5%-34.2%) in 1993 to 6.6% (95% CI, 6.4%-6.8%) in 2021. A substantial reduction in the IQR of 0-dose prevalence across states from 30.1% in 1993 to 3.1% in 2021 suggested a convergence in state disparities. The prevalence in the northeastern states of Meghalaya (17.0%), Nagaland (16.1%), Mizoram (14.3%), and Arunachal Pradesh (12.6%) remained relatively high in 2021. Prevalence increased between 2016 and 2021 in 10 states, including several traditionally high-performing states and UTs, such as Telangana (1.16 percentage points) and Sikkim (0.92 percentage points). In 2021, 53.0% of children with 0-dose status resided in the populous states of Uttar Pradesh, Bihar, and Maharashtra. A multilevel analysis comparing the share of variation at the state, district, and cluster (primary sampling unit) levels revealed that clusters accounted for the highest share of the total variation in 2016 (44.7%; VPC [SE], 1.04 [0.32]) and 2021 (64.3%; VPC [SE], 0.38 [0.12]). In this cross-sectional study, findings from approximately 3 decades of analysis suggest the need for sustained efforts to target populous states like Uttar Pradesh and Bihar and northeastern parts of India. The resurgence of 0-dose prevalence in 10 states highlights the importance of programs like Intensified Mission Indradhanush 4.0, a major national initiative to improve immunization coverage. Prioritizing small administrative units will be important to strengthening India's efforts to bring every child into the immunization regime.