Relative Prevalence Ratios Research Articles

Factors associated with self-medication in users of drugstores and pharmacies in Peru: an analysis of the National Survey on User Satisfaction of Health Services, ENSUSALUD 2015

Background: Irresponsible self-medication is a problem for health systems in developing countries. We aimed to estimate the frequency of self-medication and associated factors in users of drugstores and pharmacies in Peru. Methods: We performed a secondary data analysis of the 2015 National Survey on User Satisfaction of Health Services (ENSUSALUD), a two-stage probabilistic sample of all regions of Peru. Non self-medication (NSM), responsible self-medication (RSM) and irresponsible self-medication (ISM) were defined as the outcome categories. Demographic, social, cultural and health system variables were included as covariates. We calculated relative prevalence ratios (RPR) with their 95% confidence intervals (95%CI) using crude and adjusted multinomial logistic regression models for complex samples with NSM as the referent category. Results: 2582 participants were included. The average age was 41.4 years and the frequencies of NSM, RSM and ISM were 25.2%, 23.8% and 51.0%; respectively. The factors associated with RSM were male gender (RPR: 1.35; 95%CI: 1.06-1.72), being between 40 and 59 years old (RPR: 0.53; 95%IC: 0.39-0.72), being 60 or older (RPR: 0.39; 95%IC: 0.25-0.59), not having health insurance (RPR: 1.89; 95%CI: 1.31-2.71) and living in the Highlands region (RPR: 2.27; 95%CI: 1.23-4.21). The factors associated with ISM were male gender (RPR: 1.41; 95%CI: 1.16-1.72), being between 40 and 59 years old (RPR: 0.68; 95%IC: 0.53-0.88), being 60 or older (RPR: 0.65; 95%IC: 0.48-0.88) and not having health insurance (RPR: 2.03; 95%CI: 1.46-2.83). Conclusion: Around half of the population practiced ISM, which was associated with demographic and health system factors. These outcomes are the preliminary evidence that could contribute to the development of health policies in Peru.

Relation between opioid-related harms and socioeconomic inequalities in Ontario: a population-based descriptive study.

Negative health outcomes associated with the use of both prescribed and nonprescribed opioids are increasingly prevalent. We examined long-term trends in opioid-related harms in Ontario across a set of 6 indicators and the relation between harms and neighbourhood income in 2016. We examined rates of neonatal abstinence syndrome, opioid poisoning (fatal and nonfatal) and nonpoisoning opioid-related events from 2003 to 2016 in Ontario using population-based health administrative databases. We conducted descriptive analyses for harm indicators across neighbourhood income quintiles in 2016 (2015 for death). We examined social inequalities in opioid-related harms on both relative (prevalence ratio) and absolute (potential rate reduction) scales. Rates of opioid-related harms increased dramatically between 2003 and 2016. In 2016, neonatal abstinence syndrome and opioid poisoning and nonpoisoning events showed a strong social gradient, with harm rates being lowest in higher-income neighbourhoods and highest in lower-income neighbourhoods. Prevalence ratios for the lowest-income neighbourhoods compared to the highest-income neighbourhoods ranged from 2.36 (95% confidence interval [CI] 2.15-2.58) for emergency department visits for opioid poisoning to 3.70 (95% CI 2.62-5.23) for neonatal abstinence syndrome. Potential rate reductions for opioid-related harms ranged from 34.8% (95% CI 29.1-40.1) to 49.9% (95% CI 36.7-60.5), which suggests that at least one-third of all harmful events could be prevented if all neighbourhoods had the same socioeconomic profile as the highest-income neighbourhoods. Rates of opioid-related harms increased in Ontario between 2003 and 2016, and people in lower-income neighbourhoods experienced substantially higher rates of opioid-related harms than those in higher-income neighbourhoods. This finding can inform planning for opioid-related public health interventions with consideration of health equity.

The impact of \u201cChild Care\u201d intervention in rural Primary Health Care Program on prevalence of diarrhea among children less than 36 months of age in rural western China

BackgroundIt was unclear how and to what extent the “Child Care” intervention (CCI) in rural Primary Health Care Program affected the prevalence of childhood diarrhea in rural western China.MethodsThe available data of 10,829 and 10,682 households was collected from shared 34 counties of 9 provinces of western China in 2001 and 2005 respectively. A log-binomial regression model was used to predict the effect of CCI on prevalence of childhood diarrhea.ResultsIn 2001, the prevalence rate of diarrhea among children less than 36 months of age was 17.01% in intervention group and 17.72% in control group, and in 2005 this crude rate declined to 4.85% in the former and 6.84% in the latter. Log-binomial regression analysis showed that CCI decreased the overall prevalence of childhood diarrhea by 27% (adjusted relative prevalence ratio (rPR) = 0.73 95% CI 0.59, 0.89). The stratification regression by social-economic status (SES) of the households showed that this effect varied with SES of the households. In the medium or rich households, this intervention was effective significantly (the medium: adjusted rPR = 0.63,95%CI 0.41,0.95; the rich: adjusted rPR = 0.72,95%CI 0.54,0.97), but in poor households it seemed to be less effective (adjusted rPR = 0.86,95%CI 0.55,1.36).ConclusionIn rural Primary Health Care Program, CCI was effective in improving childhood diarrhea but this effect was inequitable among SES of the households. So, attention should be paid to the inequality when CCI was adopted to reduce childhood diarrhea in rural China.

Pre-analytical Factors Influence Accuracy of Urine Spot Iodine Assessment in Epidemiological Surveys.

Urinary iodine concentration (UIC) is commonly used to assess iodine status of subjects in epidemiological surveys. As pre-analytical factors are an important source of measurement error and studies about this phase are scarce, our objective was to assess the influence of urine sampling conditions on UIC, i.e., whether the child ate breakfast or not, urine void rank of the day, and time span between last meal and urine collection. A nationwide, two-stage, stratified, cross-sectional study including 1560 children (6-12years) was performed in 2012. UIC was determined by the Sandell-Kolthoff method. Pre-analytical factors were assessed from children's mothers by using a questionnaire. Association between iodine status and pre-analytical factors were adjusted for one another and socio-economic characteristics by multivariate linear and multinomial regression models (RPR: relative prevalence ratios). Skipping breakfast prior to morning urine sampling decreased UIC by 40 to 50μg/L and the proportion of UIC < 100μg/L was higher among children having those skipped breakfast (RPR = 3.2[1.0-10.4]). In unadjusted analyses, UIC was less among children sampled more than 5h from their last meal. UIC decreased with rank of urine void (e.g., first vs. second, P < 0.001); also, the proportion of UIC < 100μg/L was greater among 4th rank samples (vs. second RPR = 2.1[1.1-4.0]). Subjects' breakfast status and urine void rank should be accounted for when assessing iodine status. Providing recommendations to standardize pre-analytical factors is a key step toward improving accuracy and comparability of survey results for assessing iodine status from spot urine samples. These recommendations have to be evaluated by future research.

Knowledge and information levels and adherence to oral anticoagulant therapy with warfarin in patients attending primary health care services.

Background Oral anticoagulation therapy with warfarin is widely used around the world and its safety and efficacy are well-established. Nevertheless, anticoagulants are among the drug classes most associated with fatal medication errors in primary health care. Objective To investigate patient knowledge, the level of information provided, and medication adherence in patients treated with warfarin at a primary health care service. Method A cross-sectional study of a prospective cohort of 60 patients on warfarin treatment in the town of Ijuí, Rio Grande do Sul, Brazil. A questionnaire was administered to test patients’ knowledge about their prescriptions and the level of information provided by the health team. The 8-item Morisky Medication Adherence Scale (MMAS-8) and International Normalized Ratio (INR) were used to verify adherence to treatment. Results The results were expressed in absolute and relative values and prevalence ratios were calculated, with respective 95% confidence intervals. It was found that 83.3% of the participants had been given insufficient information by the health team, 50% did not know how to use the medication correctly, 86.7% were not adherent to the treatment according to MMAS-8 and 63.3% were outside of the correct INR range. Conclusion In this study, we observed a need to improve the quality of information provided to users and to develop strategies to improve adherence to treatment, to ensure the safety of patients treated with warfarin in primary health care services.

Optimal sequencing strategies for identifying disease-associated singletons.

With the increasing focus of genetic association on the identification of trait-associated rare variants through sequencing, it is important to identify the most cost-effective sequencing strategies for these studies. Deep sequencing will accurately detect and genotype the most rare variants per individual, but may limit sample size. Low pass sequencing will miss some variants in each individual but has been shown to provide a cost-effective alternative for studies of common variants. Here, we investigate the impact of sequencing depth on studies of rare variants, focusing on singletons—the variants that are sampled in a single individual and are hardest to detect at low sequencing depths. We first estimate the sensitivity to detect singleton variants in both simulated data and in down-sampled deep genome and exome sequence data. We then explore the power of association studies comparing burden of singleton variants in cases and controls under a variety of conditions. We show that the power to detect singletons increases with coverage, typically plateauing for coverage > ~25x. Next, we show that, when total sequencing capacity is fixed, the power of association studies focused on singletons is typically maximized for coverage of 15-20x, independent of relative risk, disease prevalence, singleton burden, and case-control ratio. Our results suggest sequencing depth of 15-20x as an appropriate compromise of singleton detection power and sample size for studies of rare variants in complex disease.

Healthcare Antibiotic Resistance Prevalence - DC (HARP-DC): A Regional Prevalence Assessment of Carbapenem-Resistant Enterobacteriaceae (CRE) in Healthcare Facilities in Washington, District of Columbia.

OBJECTIVE Carbapenem-resistant Enterobacteriaceae (CRE) are a significant clinical and public health concern. Understanding the distribution of CRE colonization and developing a coordinated approach are key components of control efforts. The prevalence of CRE in the District of Columbia is unknown. We sought to determine the CRE colonization prevalence within healthcare facilities (HCFs) in the District of Columbia using a collaborative, regional approach. DESIGN Point-prevalence study. SETTING This study included 16 HCFs in the District of Columbia: all 8 acute-care hospitals (ACHs), 5 of 19 skilled nursing facilities, 2 (both) long-term acute-care facilities, and 1 (the sole) inpatient rehabilitation facility. PATIENTS Inpatients on all units excluding psychiatry and obstetrics-gynecology. METHODS CRE identification was performed on perianal swab samples using real-time polymerase chain reaction, culture, and antimicrobial susceptibility testing (AST). Prevalence was calculated by facility and unit type as the number of patients with a positive result divided by the total number tested. Prevalence ratios were compared using the Poisson distribution. RESULTS Of 1,022 completed tests, 53 samples tested positive for CRE, yielding a prevalence of 5.2% (95% CI, 3.9%-6.8%). Of 726 tests from ACHs, 36 (5.0%; 95% CI, 3.5%-6.9%) were positive. Of 244 tests from long-term-care facilities, 17 (7.0%; 95% CI, 4.1%-11.2%) were positive. The relative prevalence ratios by facility type were 0.9 (95% CI, 0.5-1.5) and 1.5 (95% CI, 0.9-2.6), respectively. No CRE were identified from the inpatient rehabilitation facility. CONCLUSION A baseline CRE prevalence was established, revealing endemicity across healthcare settings in the District of Columbia. Our study establishes a framework for interfacility collaboration to reduce CRE transmission and infection. Infect Control Hosp Epidemiol 2017;38:921-929.

Tobacco use among people living with HIV: analysis of data from Demographic and Health Surveys from 28 low-income and middle-income countries.

SummaryBackgroundTobacco use among people living with HIV results in excess morbidity and mortality. However, very little is known about the extent of tobacco use among people living with HIV in low-income and middle-income countries (LMICs). We assessed the prevalence of tobacco use among people living with HIV in LMICs.MethodsWe used Demographic and Health Survey data collected between 2003 and 2014 from 28 LMICs where both tobacco use and HIV test data were made publicly available. We estimated the country-specific, regional, and overall prevalence of current tobacco use (smoked, smokeless, and any tobacco use) among 6729 HIV-positive men from 27 LMICs (aged 15–59 years) and 11 495 HIV-positive women from 28 LMICs (aged 15–49 years), and compared them with those in 193 763 HIV-negative men and 222 808 HIV-negative women, respectively. We estimated prevalence separately for males and females as a proportion, and the analysis accounted for sampling weights, clustering, and stratification in the sampling design. We computed pooled regional and overall prevalence estimates through meta-analysis with the application of a random-effects model. We computed country, regional, and overall relative prevalence ratios for tobacco smoking, smokeless tobacco use, and any tobacco use separately for males and females to study differences in prevalence rates between HIV-positive and HIV-negative individuals.FindingsThe overall prevalence among HIV-positive men was 24·4% (95% CI 21·1–27·8) for tobacco smoking, 3·4% (1·8–5·6) for smokeless tobacco use, and 27·1% (22·8–31·7) for any tobacco use. We found a higher prevalence in HIV-positive men of any tobacco use (risk ratio [RR] 1·41 [95% CI 1·26–1·57]) and tobacco smoking (1·46 [1·30–1·65]) than in HIV-negative men (both p<0·0001). The difference in smokeless tobacco use prevalence between HIV-positive and HIV-negative men was not significant (1·26 [1·00–1·58]; p=0·050). The overall prevalence among HIV-positive women was 1·3% (95% CI 0·8–1·9) for tobacco smoking, 2·1% (1·1–3·4) for smokeless tobacco use, and 3·6% (95% CI 2·3–5·2) for any tobacco use. We found a higher prevalence in HIV-positive women of any tobacco use (RR 1·36 [95% CI 1·10–1·69]; p=0·0050), tobacco smoking (1·90 [1·38–2·62]; p<0·0001), and smokeless tobacco use (1·32 [1·03–1·69]; p=0·030) than in HIV-negative women.InterpretationThe high prevalence of tobacco use in people living with HIV in LMICs mandates targeted policy, practice, and research action to promote tobacco cessation and to improve the health outcomes in this population.FundingSouth African Medical Research Council and the UK Medical Research Council.

Intracranial atherosclerosis and dementia: The Atherosclerosis Risk in Communities (ARIC) Study.

To explore the association of intracranial atherosclerotic disease (ICAD) with mild cognitive impairment (MCI) and dementia. From 2011 to 2013, 1,744 participants completed high-resolution vessel wall MRI from the population-based Atherosclerosis Risk in Communities Study by a sampling strategy that allowed weighting back to the cohort. We defined ICAD by plaque features (presence, territory, stenosis, number). Trained clinicians used an algorithm incorporating information from interviews and neuropsychological and neurologic examinations to adjudicate for MCI and dementia. We determined the relative prevalence ratio (RPR) of MCI or dementia after adjusting for risk factors at midlife using multinomial logistic regression. A total of 601 (34.5%) participants had MCI (mean age ± SD, 76.6 ± 5.2 years), 83 (4.8%) had dementia (79.1 ± 5.3 years), and 857 (49.1%) were current or former smokers. Anterior cerebral artery (ACA) plaque (adjusted RPR 3.81, 95% confidence interval [CI] 1.57-9.23), >2 territories with plaque (adjusted RPR 2.12, 95% CI 1.00-4.49), and presence of stenosis >50% (adjusted RPR 1.92, 95% CI 1.01-3.65) were associated with increased prevalence of dementia in separate models. Posterior cerebral artery plaque was associated with MCI but did not reach statistical significance for dementia (adjusted RPR MCI 1.43, 95% CI 1.04-1.98; adjusted RPR dementia 1.58, 95% CI 0.79-2.85). There were no associations with middle cerebral artery atherosclerotic lesions or cognitive impairment. Many participants had plaque in >1 territory (n = 291, 46%) and participants with ACA plaques (n = 69) had the greatest number of plaques in other territories (mean 6.0, SD 4.4). This study demonstrates associations between ICAD and clinical MCI and dementia.

Examining the role of follow-up skeletal surveys in non-accidental trauma

BackgroundDiagnosing NAT (non-accidental trauma) includes a skeletal survey to identify injuries. A follow-up survey is performed for missed injuries. This study examines the necessity of follow-up surveys. MethodsThe trauma database identified cases of suspected NAT in <4 years olds (2013–2014). Data were stratified by survey, age, injury, then analyzed for the prevalence of findings. All analyses (relative risk, prevalence and odds ratios) utilized RealStats Resource Pack (Trento, Italy). Results79% positive initial findings and no new follow up findings. Those with negative initial imaging, had no missed injuries. Initial scans were 27.6X more likely to be positive. Fractured skull (31.3), femur (17.2) and ribs (15.7) were the most prevalent. No pelvic fractures and <1% spinal injuries despite both having the greatest radiation exposure. Repeat scans rarely identify findings for age >12 months. ConclusionsFollow-up skeletal surveys maybe unnecessary without clinical evidence. Uncommon pelvic and spinal fractures may warrant exclusion from surveys unless clinically indicated.

Gender inequalities in excess adiposity and anaemia combine in a large double burden of malnutrition gap detrimental to women in an urban area in North Africa.

The nutrition transition has exacerbated the gender gap in health in the Middle East and North Africa region as the increase in excess adiposity has been much higher among women than men. This is not exclusive of the persistence of anaemia, generally also more prevalent among women. We assessed the magnitude and sociodemographic factors associated with gender inequality vis-à-vis the double burden of excess adiposity and anaemia. Cross-sectional study, stratified two-stage cluster sample. BMI (=weight/height2) ≥25·0 kg/m2 defined overweight and BMI≥30·0 kg/m2 obesity. Anaemia was defined as Hb <120 g/l for women, <130 g/l for men. Gender inequalities vis-à-vis the within-subject coexistence of excess adiposity and anaemia were assessed by women v. men relative prevalence ratios (RPR). Their variation with sociodemographic characteristics used models including gender × covariate interactions. Greater Tunis area in 2009-2010. Adults aged 20-49 years (women, n 1689; men, n 930). Gender inequalities in excess adiposity were high (e.g. overweight: women 64·9 % v. men 48·4 %; RPR=2·1; 95 % CI 1·6, 2·7) and much higher for anaemia (women 38·0 % v. men 7·2 %; RPR=8·2; 95 % CI 5·5, 12·4). They were striking for overweight and anaemia (women 24·1 % v. men 3·4 %; RPR=16·2; 95 % CI 10·3, 25·4). Gender inequalities in overweight adjusted for covariates increased with age but decreased with professional activity and household wealth score; gender inequality in anaemia or overweight and anaemia was more uniformly distributed. Women were much more at risk than men, from both over- and undernutrition perspectives. Both the underlying gender-related and sex-linked biological determinants of this remarkable double burden of malnutrition inequality must be addressed to promote gender equity in health.

Anthropometric Markers in Relation to Postprandial Hyperinsulinemia in Middle-Aged Adults

Our objective was to evaluate the relationship between postprandial hyperinsulinemia with three anthropometric markers of adiposity; body mass index (BMI), waist hip ratio (WHR) and body fat percentage (BFP). We carry out a retrospective observational study reviewed medical records of 752 patients who attended outpatient endocrinology, no previous diagnosis of metabolic disease, but with a family history of metabolic risk in the period 2012 to 2014. We collected demographic, anthropometric measurements (BMI, WHR, and BFP) and postprandial insulin values (quartiles 1, 2, 3 and 4) between 30 to 60 minutes into oral glucose tolerance test. For testing the association between anthropometric measurements and postprandial insulin quartiles, we use a univariate and multivariate multinomial logistic regression model. The measure of association is presented as relative prevalence ratio (PR) with confidence intervals (CI) at 95%. The mean age was 37.5 years ± 14.8 and 66% of the participants were women. In the univariate analysis using quartile 1 as references, quartiles 3 and 4 were associated with BMI, WHR and BFP. In multivariate analysis, quartiles 3 and 4 remained associated with markers of adiposity. BMI; PR = 1.15, 95% CI (1.10 to 1.22) and PR = 1.25, 95% CI (1.19 to 1.32) for quartiles 3 and 4; respectively. WHR; PR = 3.25, 95% CI (2.17 to 4.87) and PR = 5.85, 95% CI (3.76 to 9.10) for quartiles 3 and 4 respectively. BFP; PR = 1.09, 95% CI (1.05 to 1.12) and PR = 1.14, 95% CI (1.10 to 1.18) for quartiles 3 and 4; respectively. In conclusion, the diagnosis of obesity must be carried out using the combination of measures of adiposity in order to evaluate the total fat content and distribution of body fat.

Bayesian models as a unified approach to estimate relative risk (or prevalence ratio) in binary and polytomous outcomes.

BackgroundDisadvantages have already been pointed out on the use of odds ratio (OR) as a measure of association for designs such as cohort and cross sectional studies, for which relative risk (RR) or prevalence ratio (PR) are preferable. The model that directly estimates RR or PR and correctly specifies the distribution of the outcome as binomial is the log-binomial model, however, convergence problems occur very often. Robust Poisson regression also estimates these measures but it can produce probabilities greater than 1.ResultsIn this paper, the use of Bayesian approach to solve the problem of convergence of the log-binomial model is illustrated. Furthermore, the method is extended to incorporate dependent data, as in cluster clinical trials and studies with multilevel design, and also to analyse polytomous outcomes. Comparisons between methods are made by analysing four data sets.ConclusionsIn all cases analysed, it was observed that Bayesian methods are capable of estimating the measures of interest, always within the correct parametric space of probabilities.Electronic supplementary materialThe online version of this article (doi:10.1186/s12982-015-0030-y) contains supplementary material, which is available to authorized users.

Brachial-ankle pulse wave velocity is associated with coronary calcium in young and middle-aged asymptomatic adults: The Kangbuk Samsung Health Study.

To evaluate the association between brachial-ankle pulse wave velocity (baPWV), a convenient, non-radiating, readily available measurement of arterial stiffness, and coronary artery calcium (CAC), a reliable marker of coronary atherosclerosis, in a large sample of young and middle-aged asymptomatic adults; and to assess the incremental value of baPWV for detecting prevalent CAC beyond traditional risk factors. Cross-sectional study of 15,185 asymptomatic Korean adults who voluntarily underwent a comprehensive health screening program including measurement of baPWV and CAC. BaPWV was measured using an oscillometric method with cuffs placed on both arms and ankles. CAC burden was assessed using a multi-detector CT scan and scored following Agatston's method. The prevalence of CAC>0 and CAC>100 increased across baPWV quintiles. The multivariable-adjusted odds ratios (95% CI) for CAC>0 comparing baPWV quintiles 2-5 versus quintile 1 were 1.06 (0.87-1.30), 1.24 (1.02-1.50), 1.39 (1.15-1.69) and 1.60 (1.31-1.96), respectively (P trend<0.001). Similarly, the relative prevalence ratios for CAC>100 were 1.30 (0.74-2.26), 1.59 (0.93-2.71), 1.74 (1.03-2.94) and 2.59 (1.54-4.36), respectively (P trend<0.001). For CAC>100, the area under the ROC curve for baPWV alone was 0.71 (0.68-0.74), and the addition of baPWV to traditional risk factors significantly improved the discrimination and calibration of models for detecting prevalent CAC>0 and CAC>100. BaPWV was independently associated with the presence and severity of CAC in a large sample of young and middle-aged asymptomatic adults. BaPWV may be a valuable tool for identifying apparently low-risk individuals with increased burden of coronary atherosclerosis.

Frequency, severity and predictors of playing-related musculoskeletal pain in professional orchestral musicians in Germany

Playing-related musculoskeletal disorders (PRMD) in professional musicians are common. Existing literature demonstrates that up to 86 % of musicians are affected. The aim of the study was to evaluate the frequency of musculoskeletal pain in professional orchestral musicians with regard to their instrument affiliation. Of special interest were pain intensity and its association with predictors such as gender, instrument group, age or stage fright. Professional orchestra players completed a self-report questionnaire to assess playing-related musculoskeletal pain and its frequency and intensity in various body regions on a numeric rating scale (NRS). Relative frequencies and prevalence ratios for different instrument groups were estimated. Out of 720 approached musicians, 408 were included in the sample (response rate 57 %); overall, 89.5 % had been affected by current or past playing-related musculoskeletal pain, 62.7 % reported pain in the previous 3 months, and 8.6 % reported current pain. Pain distribution and frequency varied between instrument groups. For all instrument groups, the neck was the most common pain region. About 43 % of musicians presented more than five pain regions, in particular violin players. Approximately 40 % of musicians indicated frequent or permanent pain. Average pain intensities increased from NRS 3.8 up to a range of 5.9 and 7.4 for frequent and permanent pain, respectively. Female gender and stage fright were proven to be predictors for musculoskeletal pain. Professional orchestral musicians are greatly affected by PRMD, often experiencing frequent or permanent pain, high pain levels and pain in various body regions. As PRMD might contribute considerably to performance disability, sick leave and the possibility of premature termination of a musicians' career, this study highlights the necessity for tailored therapeutic and preventive strategies in performing arts medicine.

Bias of using odds ratio estimates in multinomial logistic regressions to estimate relative risk or prevalence ratio and alternatives

Recent studies have emphasized that there is no justification for using the odds ratio (OR) as an approximation of the relative risk (RR) or prevalence ratio (PR). Erroneous interpretations of the OR as RR or PR must be avoided, as several studies have shown that the OR is not a good approximation for these measures when the outcome is common (&gt; 10%). For multinomial outcomes it is usual to use the multinomial logistic regression. In this context, there are no studies showing the impact of the approximation of the OR in the estimates of RR or PR. This study aimed to present and discuss alternative methods to multinomial logistic regression based upon robust Poisson regression and the log-binomial model. The approaches were compared by simulating various possible scenarios. The results showed that the proposed models have more precise and accurate estimates for the RR or PR than the multinomial logistic regression, as in the case of the binary outcome. Thus also for multinomial outcomes the OR must not be used as an approximation of the RR or PR, since this may lead to incorrect conclusions.

Symptoms of craniomandibular dysfunction in professional orchestra musicians

Up to 80% of professional musicians are affected by playing-related musculoskeletal disorders, but data regarding the frequency of craniomandibular dysfunction (CMD) in professional orchestra musicians is scarce. To evaluate the frequency of CMD and its relation to musculoskeletal pain in various body regions. A questionnaire-based survey approach assessing CMD symptoms and musculoskeletal pain in professional orchestra players was adopted. Relative prevalence rates and prevalence ratios for different instrument groups were estimated. A total of 408 musicians completed the questionnaire (response rate 57%). Playing-related pain in the teeth or jaw was reported by 19-47% of musicians and TMJ pain by 15-34%, depending on the instrument group. Current pain in the face indicating a painful CMD was reported in 6-10% and related symptoms such as teeth grinding in 25-34%, jaw clenching in 33-42% and jaw locking in 11-18% of musicians. Females were 2.4 times (95% confidence intervals (CI) 1.49-3.84) more likely to report having had orofacial pain within the last month. Musicians reporting orofacial pain within the last month were 4.8 times (95% CI: 2.83-8.02) more likely to report pain in the neck and 2.5-3.8 times (P < 0.05) more likely to report pain in other body regions, including shoulders, right wrist, left fingers and the thoracic and lumbar spine. Symptoms suggesting CMD were common in this study of professional orchestra musicians and were associated with pain in the neck, shoulder and hands. There is a need to enhance awareness of CMD to optimize early medical diagnosis and treatment.

The Association of Serum Lipids With Colorectal Adenomas

There is suggestive but sparse evidence that dyslipidemia is associated with colorectal neoplasms. We investigated the association of serum lipid and apolipoprotein concentrations with the prevalence of colorectal adenomas. Cross-sectional study of 19,281 consecutive participants aged 40-79 years undergoing screening colonoscopy at the Center for Health Promotion of the Samsung Medical Center in Korea from January 2006 to June 2009. We identified 5,958 participants with colorectal adenomas (30.9%), including 5,504 (28.5%) with non-advanced adenomas and 454 (2.4%) with advanced adenomas. The adjusted relative prevalence ratios (aRPRs) comparing the fourth with the first quartiles of serum triglycerides were 1.35 (95% confidence interval (CI) 1.20-1.52; P trend<0.001) for non-advanced adenomas and 1.45 (95% CI 1.02-2.06; P trend=0.005) for advanced adenomas. Higher levels of high-density lipoprotein (HDL) cholesterol and apolipoprotein A-1 (ApoA-1) were significantly associated with 12% (Q4 vs. Q1 aRPR 1.12; 95% CI 1.00-1.26; P trend=0.049) and 17% (Q4 vs. Q1 aRPR 1.17; 95% CI 1.04-1.31; P trend=0.004) higher prevalence of non-advanced adenoma. There was also a non-significant association between higher levels of low-density lipoprotein (LDL) cholesterol (Q4 vs. Q1 aRPR 1.22; 95% CI 0.91-1.66; P trend= 0.12) and apolipoprotein B (ApoB) (Q4 vs. Q1 aRPR 1.32; 95% CI 0.94-1.83; P trend=0.07) with higher prevalence of advanced adenoma. There was no association between total cholesterol levels with colorectal adenoma. In this large cross-sectional study, higher levels of serum triglycerides were significantly associated with an increasing prevalence of both non-advanced and advanced colorectal adenomas, while higher levels of ApoA-1 and HDL cholesterol were significantly associated with an increasing prevalence of non-advanced adenomas.

A simple method for estimating relative risk using logistic regression

BackgroundOdds ratios (OR) significantly overestimate associations between risk factors and common outcomes. The estimation of relative risks (RR) or prevalence ratios (PR) has represented a statistical challenge in multivariate analysis and, furthermore, some researchers do not have access to the available methods. Objective: To propose and evaluate a new method for estimating RR and PR by logistic regression.MethodsA provisional database was designed in which events were duplicated but identified as non-events. After, a logistic regression was performed and effect measures were calculated, which were considered RR estimations. This method was compared with binomial regression, Cox regression with robust variance and ordinary logistic regression in analyses with three outcomes of different frequencies.ResultsORs estimated by ordinary logistic regression progressively overestimated RRs as the outcome frequency increased. RRs estimated by Cox regression and the method proposed in this article were similar to those estimated by binomial regression for every outcome. However, confidence intervals were wider with the proposed method.ConclusionThis simple tool could be useful for calculating the effect of risk factors and the impact of health interventions in developing countries when other statistical strategies are not available.

Diagnosis of Congenital Portosystemic Shunt in Miniature Schnauzers 7 Years of Age or Older (1997–2006)

Dogs with congenital portosystemic shunt (PSS) are typically diagnosed before 2 years of age. The objective of this study was to determine if miniature schnauzers are more likely to be diagnosed with congenital PSS at an older age than are other breeds. This retrospective study examined the case records of 171 dogs diagnosed with congenital PSS; dogs were included if they were definitively diagnosed as having congenital PSS by nuclear scintigraphy, contrast portography, and/or exploratory surgery. Seven (23%) of 31 miniature schnauzers diagnosed with congenital PSS were 7 years of age or older at the time of diagnosis, compared to 3.4% for all other breeds. Miniature schnauzers had a relative prevalence ratio of 6.3 (95% confidence interval 2.2 to 18.6; P=0.001) for being diagnosed at or after 7 years of age when compared to all other breeds of dogs. Clinical signs of congenital PSS may not manifest sufficiently to cause an owner to seek veterinary care for some dogs until they are older. Congenital PSS should be considered in mature dogs, particularly miniature schnauzers, that are presented with signs potentially consistent with hepatic encephalopathy.