National Population-based Surveys Research Articles

Secondary analysis of national and subnational survey data to evaluate the impact of the scale-up of malaria control interventions in Malawi, 2000–10

BackgroundMalaria control interventions, including insecticide-treated nets (ITNs), were scaled up nationwide in Malawi during 2000–10. We assessed trends and associations of ITN coverage, malaria morbidity, and all-cause mortality in children under 5 years of age under programmatic conditions in Malawi during 2000–10. MethodsTrends in household ITN ownership, malaria parasitaemia, and anaemia (haemoglobin <80 g/L) prevalence, and all-cause under-5 mortality per 1000 livebirths (ACCM) were assessed from national population-based household surveys conducted during 2000–10. Random-effects logistic regression models assessed the association between household ITN ownership and malaria parasitaemia, or anaemia prevalence in children 6–30 months of age using subnational anaemia and parasitaemia survey data. We employed a random-effects Poisson regression model to assess the association between district ITN distributions and child malaria cases using integrated disease surveillance and response (IDSR) facility data. At the district level, we used a Poisson regression model to assess the association between household ITN ownership and child mortality using data from the 2010 Malawi Demographic and Health Survey. FindingsHousehold ITN ownership increased from 27·4% (95% CI 25·9–29·0) in 2004, to 56·8% (55·6–58·1) in 2010. Malaria parasitaemia decreased from 60·5% (95% CI 53·0–68·0) in 2001, to 20·4% (15·7–25·1) in 2009, in children aged 6–35 months. Anaemia decreased from 20·4% (95% CI 17·3–24·0) in 2004, to 13·1% (11·0–15·4) in 2010, in children aged 6–23 months. ACCM decreased by 41% from 188·3 deaths per 1000 livebirths (95% CI 179·2–197·3) during 1996–2000, to 112·1 per 1000 livebirths (106·1–118·0) during 2006–10. Household ITN ownership was protective against malaria parasitaemia (odds ratio 0·81, 95% CI 0·72–0·92) and anaemia (0·77, 0·70–0·86) after controlling for other covariates. ITN distributions per 1000 population were not significantly associated with malaria cases at IDSR facilities. District-level household ITN ownership was significantly associated with child survival (incidence rate ratio 0·55, 95% CI 0·31–0·99) after controlling for other covariates. InterpretationHousehold ITN ownership was protective against malaria parasitaemia, anaemia, and child mortality. Scale-up of malaria control interventions during 2000–10 was likely associated with improved child survival in Malawi. FundingFinancial support for this study was received from the United States President's Malaria Initiative.

Measuring socio‐economic inequalities in edentate Scottish adults – cross‐sectional analyses using Scottish Health Surveys 1995–2008/09

To investigate the appropriateness of different measures of socio-economic inequalities, in relation to adult oral health in Scotland, utilizing data from a series of large, representative population surveys. The Scottish Health Surveys (SHeS) (1995; 1998; 2003; 2008/09) are cross-sectional national population-based surveys used to monitor health status in those living in private households. The age groups included in this study are as follows: 45-54; 55-64 years: all survey years; 65-74: 1998 onwards; 75+: 2003 onwards. Primary outcome was no natural teeth (edentulism). Three measures of socio-economic position: Occupational social class, Education, Carstairs deprivation score (2001) were used. Simple (absolute/relative differences) and complex measures (Slope Index, Relative Index, Concentration Index and c-index) of inequality were produced for each age group across all four surveys. Simple and complex (absolute) measures of inequality have both demonstrated narrowing disparities in edentulism over time in the 45- to 64-year-old group, a levelling off in those aged 65 and above, and a rise in those aged 75+. Complex relative measures (RII, Concentration Index and c-index), however, show an increasing trend in inequalities over time for all age groups, suggesting that rates of improvement in edentulism rates are not uniform across all social groups. Simple absolute inequality provides a quick and easy indication of the extent of disparities between extreme groups, whereas complex measures (absolute and relative) consider the gradient in health across all social groups. We have demonstrated that both are useful measures of inequality and should be considered complementary to one another. The appropriate choice of complex measure of inequality will depend on the audience to whom the results are to be communicated. This methodological approach is not confined to oral health but is applicable to other health outcomes that are socially patterned.

The Variability of Vision Loss Assessment in Federally Sponsored Surveys: Seeking Conceptual Clarity and Comparability

To review U.S. national population-based surveys to evaluate comparability and conceptual clarity of vision measures. Perspective. The vision questions in 12 surveys were mapped to the World Health Organization's International Classification of Functioning, Disability and Health framework under the domains of condition, impairment, activity limitation, participation, and environment. Surveys examined include the National Health Interview Survey, the Behavioral Risk Factor Surveillance Survey, National Health and Nutrition Examination Survey, the Census, and the Visual Function Questionnaire. Nearly 100 vision measures were identified in 12 surveys. These surveys provided no consistent measure of vision or vision impairment. Survey questions asked about differing characteristics of vision-related disease, function, and social roles. A question related to ability to read newspaper print was the most commonly asked question in surveys. Limited comparability of data and lack of conceptual clarity in the population-based surveys resulted in an inability to consistently characterize the population of people experiencing vision impairment. Consequently, vision surveillance was limited.

Initial Validation of an Exercise “Vital Sign” in Electronic Medical Records

The objective of this study is to describe the face and discriminant validity of an exercise vital sign (EVS) for use in an outpatient electronic medical record. Eligible patients were 1,793,385 adults 18 yr and older who were members of a large health care system in Southern California. To determine face validity, median total self-reported minutes per week of exercise as measured by the EVS were compared with findings from national population-based surveys. To determine discriminant validity, multivariate Poisson regression models with robust variance estimation were used to examine the ability of the EVS to discriminate between groups of patients with differing physical activity (PA) levels on the basis of demographics and health status. After 1.5 yr of implementation, 86% (1,537,798) of all eligible patients had an EVS in their electronic medical record. Overall, 36.3% of patients were completely inactive (0 min of exercise per week), 33.3% were insufficiently active (more than 0 but less than 150 min·wk), and 30.4% were sufficiently active (150 min or more per week). As compared with national population-based surveys, patient reports of PA were lower but followed similar patterns. As hypothesized, patients who were older, obese, of a racial/ethnic minority, and had higher disease burdens were more likely to be inactive, suggesting that the EVS has discriminant validity. We found that the EVS has good face and discriminant validity and may provide more conservative estimates of PA behavior when compared with national surveys. The EVS has the potential to provide information about the relationship between exercise and health care use, cost, and chronic disease that has not been previously available at the population level.

Experience of Low Mood and Suicidal Behaviors Among Adolescents in Vietnam: Findings from Two National Population-Based Surveys

To date, no population-based data about experiences of low mood and suicidal behaviors among adolescents in Vietnam have been published in the English peer-reviewed literature. The aim was to establish the prevalence of self-reported symptoms of low mood, acts of self-harm, and suicidal thoughts and their correlates among adolescents from two national population-based surveys, Survey Assessment of Vietnamese Youth (SAVY) I (2003-2004) and II (2009-2010). Data from the subset of participants aged 14-19 years from the two structured SAVYs were analyzed. Descriptive and bivariate statistics were used to test for between-group comparisons. Multiple logistic regressions were performed to determine factors associated with low mood and suicidal ideation. A weighting factor was used in all analyses. Prevalence of experiences of low mood was 34.06% in SAVY I and 37.34% in SAVY II; prevalence of suicidal behaviors was 5.28% (SAVY I) and 12.21% (SAVY II). Significant risk factors were being female, an ethnic minority, illiterate, or exposed to violence; perceiving study load as too heavy; following a religion other than Buddhism; or living in wealthier families. Better family cohesion protected adolescents from these unfavorable outcomes. Alcohol use co-occurred significantly with experiences of low mood and suicidal behaviors. Self-reported lifetime experiences of low mood are common among Vietnamese adolescents, with signs of an increasing trend. Suicidal behaviors are less prevalent than in other settings but are also increasing. Further research is warranted to elucidate these findings and to inform interventions to optimize the mental health of adolescents in Vietnam.

Taking in the View From 30 000 Feet

The availability of population-based survey data provides a unique opportunity to understand issues related to access and utilization of physical therapy in the United States, and to better gauge public perceptions of the profession. In our day-to-day routine, we all tend to consider our work as physical therapists on a one-to-one level with the patients we serve. Examining data from national population-based surveys can elevate our daily, ground-level viewpoint to a 30 000-foot perspective on the profession. This vantage point allows certain things to come into focus that would otherwise be obscured, and the vision may not always comport with our expectations. J Orthop Sports Phys Ther 2011;41(7):465–466. doi:10.2519/jospt.2011.0105

Estimating HIV Incidence among Adults in Kenya and Uganda: A Systematic Comparison of Multiple Methods

BackgroundSeveral approaches have been used for measuring HIV incidence in large areas, yet each presents specific challenges in incidence estimation.Methodology/Principal FindingsWe present a comparison of incidence estimates for Kenya and Uganda using multiple methods: 1) Epidemic Projections Package (EPP) and Spectrum models fitted to HIV prevalence from antenatal clinics (ANC) and national population-based surveys (NPS) in Kenya (2003, 2007) and Uganda (2004/2005); 2) a survey-derived model to infer age-specific incidence between two sequential NPS; 3) an assay-derived measurement in NPS using the BED IgG capture enzyme immunoassay, adjusted for misclassification using a locally derived false-recent rate (FRR) for the assay; (4) community cohorts in Uganda; (5) prevalence trends in young ANC attendees. EPP/Spectrum-derived and survey-derived modeled estimates were similar: 0.67 [uncertainty range: 0.60, 0.74] and 0.6 [confidence interval: (CI) 0.4, 0.9], respectively, for Uganda (2005) and 0.72 [uncertainty range: 0.70, 0.74] and 0.7 [CI 0.3, 1.1], respectively, for Kenya (2007). Using a local FRR, assay-derived incidence estimates were 0.3 [CI 0.0, 0.9] for Uganda (2004/2005) and 0.6 [CI 0, 1.3] for Kenya (2007). Incidence trends were similar for all methods for both Uganda and Kenya.Conclusions/SignificanceTriangulation of methods is recommended to determine best-supported estimates of incidence to guide programs. Assay-derived incidence estimates are sensitive to the level of the assay's FRR, and uncertainty around high FRRs can significantly impact the validity of the estimate. Systematic evaluations of new and existing incidence assays are needed to the study the level, distribution, and determinants of the FRR to guide whether incidence assays can produce reliable estimates of national HIV incidence.

Statistical Considerations in Determining HIV Incidence from Changes in HIV Prevalence

The development of methods for estimating HIV incidence is critical for tracking the epidemic and for designing, targeting and evaluating HIV prevention efforts. One method for estimating incidence is based on changes in HIV prevalence. That method is attracting increased attention because national population-based HIV prevalence surveys, such as Demographic and Health Surveys, are being conducted throughout the world. Here, we consider some statistical issues associated with estimating HIV incidence from two population-based HIV prevalence surveys conducted at two different points in time. We show that the incidence estimator depends on the relative survival rate. We evaluate the sensitivity of estimates to incorrect assumptions about the relative survival rate, and show that small errors in the relative survival can, in some situations, create large biases in HIV incidence. We determine sample sizes of prevalence surveys to estimate incidence with precision and show how the sample sizes depend on baseline prevalence, the relative survival rate, and the population HIV incidence rate. We find that even if the relative survival rate were known exactly, there are situations where prohibitively large prevalence surveys would be required to produce reliable incidence estimates. These situations can occur either when the baseline prevalence is large, the relative survival rate is near 1, or the population incidence is small. Because information on the relative survival rate may be limited or not specific to the population under study, we suggest an approach to empirically estimate this critical parameter by augmenting population-based prevalence surveys with a mortality follow-up sub-study. We determine sample sizes of the prevalence surveys and mortality sub-studies for this augmented design and provide the necessary R code (version 2.13.0) for sample size determinations. We conclude that caution should be exercised when solely relying on changes in prevalence as the method for determining HIV incidence because of the method's sensitivity to mortality assumptions and the very large sample size requirements in some settings.

Creating synergies for health systems strengthening through partnerships in Pakistan - a case study of the national eye health programme

Blindness and visual impairment are major causes of noncomrnunicable diseases in Pakistan. Two national population-based blindness surveys conducted in 1988 and 2002-04 demonstrated a reduction in prevalence of blindness from 1.78% to 0.9% with a significant drop in cataract blindness as a result of accelerated nationwide interventions and eye care integration in primary health care. In addition, between 2006 and 2008, 88 facilities were upgraded as a result of the national eye health programme. These measures resulted in a 279% increase in eye outpatient attendances and a 375% increase in eye surgeries performed. Investment in human resources development and policy change contributed significantly to the sustainability of the programme. Key challenges facing the programme include aligning national eye health strategies with health system strengthening informed through health systems research. This paper attempts to document this extraordinary success.

Beyond detuning: 10 years of progress and new challenges in the development and application of assays for HIV incidence estimation

Beyond detuning: 10 years of progress and new challenges in the development and application of assays for HIV incidence estimation

Trends in HIV prevalence and sexual behaviour among young people aged 15–24 years in countries most affected by HIV

ObjectivesIn 2001 the United Nations (UN) Declaration of Commitment was signed by 189 countries with a goal to reduce HIV prevalence among young people by 25% by 2010. Progress towards...

Burn injury and the impact on global health

BackgroundBurn injury is a serious and under-recognized global public health problem. Citizens of low and middle income countries (LMIC) bear the largest burden, accounting for 95% of fatal fire-related burns....

Using collaborative learning to improve diabetes care and outcomes: The VIDA project

The prevalence of diabetes in Mexico among those 20–64 years of age has increased from 7.2% in 1993 to 10.7% in 2000. National population-based surveys in Mexico demonstrated that 50% of the total population with diabetes had blood glucose levels of 200 mg/dl or higher. Thus, diabetes care has become one of the most important public health challenges in this country. The aim of the study was to improve the quality of diabetes care in primary health care centers using the chronic care model and the breakthrough series (BTS) collaborative methodology. Methods Ten public health centers in the cities of Xalapa and Veracruz were randomly selected to participate in the project. Five of the health centers were randomly assigned to receive the intervention (intervention group) and the other five followed usual care (usual care group). The intervention was evaluated by A1c test before and after the intervention in both groups of patients. Patients were followed for 18 months from November 2002 to May 2004. Results were adjusted for the clustering of patients within practices and baseline measure. Results The proportion of people with good glycemic control (A1c < 7%) among those in the intervention group increased from 28% before the intervention to 39% after the intervention. The proportion of patients achieving three or more quality improvement goals increased from 16.6% to 69.7% ( p < 0.001) among the intervention group while the usual care group experienced a non-significant decrease from 12.4% to 5.9% ( p = 0.118). The focus on the primary care team and the participation of people with diabetes were strategic elements incorporated into the methodology, expected to ensure sustainability of continued improvement of health outcomes. Conclusions The intervention introduced modifications to solve problems identified by health teams in their practice and improved process and outcome measures of quality diabetes care. Most of the actions were directed at four components of the chronic care model: self-management support, decision support, delivery system design, and clinical information systems.

The impact of the prevention programme of hepatitis C over more than a decade: the French experience

To assess the impact of the French national hepatitis C prevention programme initiated in 1999, we analysed trends in hepatitis C virus (HCV) prevalence, testing and characteristics of HCV-infected patient at first referral from 1994 to 2006. We used four data sources: Two national population-based sero-prevalence surveys carried out in 1994 and 2004; two surveillance networks, one based on public and private laboratories throughout France and the other on hepatology reference centres, which aim to monitor, respectively, trends of anti-HCV screening and of epidemiological-clinical characteristics of HCV patients at first referral. Between 1994 and 2004, the anti-HCV prevalence for adults aged 20-59 years decreased from 1.05 (95% confidence interval 0.75-1.34) to 0.71 (0.52-0.97). During the same period, those anti-HCV positive with detectable HCV RNA decreased from 81 to 57%, whereas, the proportion of anti-HCV positive persons aware of their status evolved from 24 to 56%. Anti-HCV screening activity increased by 45% from 2000 to 2005, but decreased in 2006 (-10%), while HCV positivity among those tested decreased from 4.3 to 2.9%. The proportion of cirrhosis at first referral remains around 10% between 2001 and 2006, with many patients with excessive alcohol consumption (34.7% among males) or viral co-infections (HIV seropositivity for 5.2% patients). Our analysis indicates that the national programme had a positive impact at the population level through improved prevention, screening and management. There is still a need to identify timely those at risk for earlier interventions, to assess co-morbidities better and for a multidisciplinary approach to HCV management.

Advances and future directions in HIV surveillance in low- and middle-income countries

To present recent advances in HIV/AIDS surveillance methods in low- and middle-income countries. From 2001 to 2008, 30 low- and middle-income countries implemented national population-based surveys with HIV testing. Antenatal clinic HIV sentinel surveillance sites in sub-Saharan Africa increased from just over 1000 in 2003-2004 to almost 2500 in 2005-2006, becoming more representative of rural areas. Between 2003 and 2007, at least 122 behavioral surveys in low- and middle-income countries used respondent-driven sampling for surveillance among high-risk populations, although many countries with concentrated epidemics continue to have major sentinel surveillance gaps. Improvements have been made in modeling estimates of number of persons HIV infected, and systems are now in place to measure HIV drug resistance. However, the reliable monitoring of trends and the measuring of HIV incidence, morbidity, and mortality is still a challenge. In the past 5 years, there have been substantial improvements in the quantity and quality of HIV surveillance studies, especially in the countries with high prevalence. Further efforts should be made in countries that lack fully implemented surveillance systems to improve HIV incidence, morbidity, and mortality surveillance and to use data more effectively.

State Regulations Have Not Decreased Indoor Tanning by Adolescents

Dermatology| May 01 2009 State Regulations Have Not Decreased Indoor Tanning by Adolescents AAP Grand Rounds (2009) 21 (5): 52. https://doi.org/10.1542/gr.21-5-52 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation State Regulations Have Not Decreased Indoor Tanning by Adolescents. AAP Grand Rounds May 2009; 21 (5): 52. https://doi.org/10.1542/gr.21-5-52 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search nav search search input Search input auto suggest search filter All AAP SitesAll PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP News Search Advanced Search Topics: artificial tanning Source: Cokkinides V, Weinstock M, Lazovich D, et al. Indoor tanning use among adolescents in the US, 1998 to 2004. Cancer. 2009;115(1):190–198; doi:10.1002/cncr.24010 Investigators from the American Cancer Society, Brown University, and the University of Minnesota assessed the change in the prevalence of indoor tanning among US adolescents between 1998 and 2004. During this period legislation regulating youth access to indoor tanning facilities was passed in 11 states; eight states had such policies prior to 1998.1,2 In 1998 and 2004, the American Cancer Society conducted national population-based cross-sectional telephone surveys of behaviors related to skin cancer risk among 11- to 18-year-old youths and their caregivers. Both adolescents and their caregivers were asked questions regarding use of indoor tanning booths or sunlamps, frequency of use of indoor tanning in the past year,... Copyright © 2009 by the American Academy of Pediatrics2009 You do not currently have access to this content.

Prévalences du VIH en Afrique sub-saharienne

In 2008 UNAIDS global report on AIDS, the number of people living with HIV in sub-Saharan Africa was estimated at 22 millions in 2007 and 20.4 millions in 2001, while in the 2002 report, the same estimation for 2001 was 28.5 millions. Changes in UNAIDS reflects evolutions of data sources and methods used for the estimates. Sentinel surveillance of pregnant women attending antenatal clinics (ANC) was developed in 1980's with the WHO recommendation of unlinked anonymous testing approach. The objective was not to be representative but to monitor trends. In the 1990's, as ANC data were available, they were used by EpiModel, a model developed by WHO for HIV prevalence estimates from 1992 to 2000. In 2002, a new epidemiological model called EPP (Estimation and Projection Package) was developed by the UNAIDS Reference Group on Estimates, Modelling and Projections, which, in countries with a generalised epidemic, is still based on ANC data collected over time. Since 2001, many countries have conducted national population-based surveys (NPS). Their results have often diverged from estimates based on ANC data. This was explained by the under-representation of rural clinics in sentinel surveillance and relative small participation rate in NPS. Since, several studies have shown that the impact of several biases (participation rate, non-household members, serological window of tests...) in NPS remains relatively low. NPS constitute a good indicator of HIV prevalence level. If pregnant women can be locally representative of the general population, at the national scale, it depends of the localization of selected clinics. But ANC provides data over time, which is not the case for NPS. The current approach of UNAIDS consists in estimating HIV prevalence trends from ANC and the level of the epidemics from NPS. But the hypothesis that ANC data are representative of trends still needs to be verified when several NPS will be available for a same country.

The epidemiology of HIV infection among young people aged 15–24 years in southern Africa

To investigate epidemiological patterns and trends of HIV infection and sexual behaviour among young people aged 15-24 years in the nine countries in southern Africa most affected by the HIV epidemic. Data on HIV prevalence among young people in the general population were obtained from national population-based surveys conducted between 2000 and 2007, whereas data on sexual behaviour were obtained from repeat surveys between 1994 and 2007. Linear or exponential regression was used to analyse HIV prevalence trends among young women attending antenatal clinics in recent years. Patterns of HIV infection among young people are similar across the countries included in this analysis. The prevalence of HIV increases after the age of 15 years, more rapidly among women than among men, reaching a peak among women in their twenties and men in their thirties. Between 2000 and 2007 the prevalence of HIV among antenatal clinic attendees was constant in Mozambique and South Africa and declining in Lesotho, Namibia, Swaziland, Zambia, Botswana, Malawi and Zimbabwe, but only reached statistical significance (P < 0.05) in the last three. Changes towards safer sexual behaviour were observed over time among young men and women in the general population in this region. Sexual behaviour changes among young people are encouraging and are associated with declines in HIV prevalence among young antenatal clinic attendees over time. More research is needed to understand the recent changes and the very high prevalence among young women in this region. Interventions aimed at reducing risky behaviour need to be supported and expanded while incorporating new approaches to prevention.

Comparison of adult HIV prevalence from national population-based surveys and antenatal clinic surveillance in countries with generalised epidemics: implications for calibrating surveillance data

Background:Estimates of the impact of HIV in countries with generalised epidemics are generally based on antenatal clinic surveillance data collected over time. In an attempt to obtain geographically more representative...

The quality of sero-surveillance in low- and middle-income countries: status and trends through 2007

Objective:To examine the quality of HIV sero-surveillance systems in 127 low-income and middle-income countries by 2007, as well as gaps in data needed for reliable estimates of HIV prevalence and...