A Population-based Case–control Study of Isolated Anophthalmia and Microphthalmia

The purpose of the study was to reveal the etiological factors in the origin of isolated an/microphthalmia. The dataset of the Hungarian Case–Control Surveillance of Congenital Abnormalities, 1980–2002 containing 56 cases with isolated an/microphthalmia and 22,744 malformed controls with other non-ocular defects from the Hungarian Congenital Abnormality Registry, in addition of 56 matched control pairs and 37,837 population controls without defects from the National Birth Registry, was evaluated. Exposure data and family history were collected (i) prospectively by prenatal logbook and other medical records, (ii) retrospectively through a structured questionnaire filled-in by mothers, and (iii) information obtained by regional nurses at home visit of non-respondent mothers. The autosomal recessive origin of isolated an/microphthalmia was indicated in about 10% of cases on the basis of sib recurrence. Cases with isolated an/microphthalmia had a much shorter mean gestational age and smaller mean birth weight, a much larger proportion of preterm birth and low birthweight. Their mothers were younger with a predominance of first birth order, frequently unmarried with low socioeconomic status. These findings are in agreement with a much higher prevalence at birth of cases with isolated an/microphthalmia in the gypsy population probably due to the interaction of inbreeding effect and low socioeconomic status. Further molecular genetic studies are needed to identify gene mutations of isolated an/microphthalmia in the Hungarian gypsy population.     

Polio vaccines: WHO position paper,March 2016–recommendations

This article presents the World Health Organization’s (WHO) recommendations on the use of polio vaccine excerpted from the WHO position paper on polio vaccines – March 2016, published in the Weekly Epidemiological Record [1]. This position paper on polio vaccines replaces the 2014 WHO position paper [2]. The position paper summarizes the WHO position on the introduction of at least one dose of inactivated polio vaccine (IPV) into routine immunization schedules as a strategy to mitigate the potential risk of re-emergence of type 2 polio following the withdrawal of Sabin type 2 strains from oral polio vaccine (OPV) [3].Footnotes to this paper provide a number of core references including references to grading tables that assess the quality of the scientific evidence, and to the evidence-to-recommendation table. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO’s current position on the use of vaccines in the global context. This position paper reflects the global switch from trivalent to bivalent OPV which took place in April 2016. Recommendations on the use of polio vaccines have been discussed on multiple occasions by SAGE, most recently in October 2016; evidence presented at these meetings can be accessed at: http://www.who.int/immunization/sage/previous/en/index.html.     

Case–control study of knee osteoarthritis and lifestyle factors considering their interaction with physical workload

Aims

The aim of this study is to examine the dose–response relationships between age, “lifestyle factors” (body mass index, tobacco smoking, sports), and symptomatic knee osteoarthritis in a population-based case–control study. Additionally, the study aims to investigate the mode of interaction between body mass index (BMI) and physical workload (occupational kneeling/squatting and lifting/carrying of loads) with respect to the risk of symptomatic knee osteoarthritis.

Methods

In five orthopedic clinics and five practices, 295 male patients aged 25–70 with radiographically confirmed knee osteoarthritis associated with chronic complaints were recruited. The control group comprised 327 male control subjects. In a structured personal interview, body weight at different ages, body height, cumulative amount of smoking, and cumulative duration of different sports activities until the date of first diagnosis of knee osteoarthritis were elicited. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis. An interaction analysis for the parameters BMI and kneeling/squatting respective lifting/carrying of loads was performed. Population attributable risks (PAR) for knee osteoarthritis were determined for BMI solely and for the combination of BMI with occupational kneeling/squatting and lifting/carrying of loads, respectively.

Results

Age and overweight were strongly associated with the diagnosis of knee osteoarthritis. Compared with persons less than 35 years old, persons who were at least 65 years old had an odds ratio (OR) of 19.0 (95% CI 6.1–58.7) for knee osteoarthritis. Persons with a BMI ≥ 28.41 kg/m² had a strongly elevated risk of knee osteoarthritis (OR 10.8; 95% CI 4.8–24.3) compared to persons with a BMI < 22.86 kg/m². Heavy tobacco smoking (≥55.5 pack years) was associated with a decreased knee osteoarthritis risk in comparison with never-smoking (OR 0.2; 95% CI 0.1–0.5). Ball games (handball, volleyball, basketball) and cycling were associated with symptomatic knee osteoarthritis (OR 4.0; 95% CI 1.8–8.9 and OR 3.7; 95% CI 1.7–7.8 in the highest category of cumulative duration, respectively); to a weaker degree jogging, swimming, and soccer also were positively related to symptomatic knee osteoarthritis. Combining the two parameters, BMI and kneeling/squatting into one variable led to a multiplicative interaction mode for symptomatic knee osteoarthritis. For persons with elevated BMI in combination with moderate to high exposure to occupational kneeling/squatting, the population attributable risk (PAR) was 4%. The PAR for elevated BMI in combination with moderate to high exposure to occupational lifting/carrying of loads was 7%.

Conclusions

In accordance with the literature, we find a strong association between BMI and knee osteoarthritis risk. Considering the relatively high prevalence of occupational manual materials handling, prevention of knee osteoarthritis should not only focus on body weight reduction, but should also take into account work organizational measures particularly aiming to reduce occupational lifting and carrying of loads.     

Traffic-Related Air Pollution and Perinatal Mortality: A Case–Control Study

Background

Ambient levels of air pollution may affect the health of children, as indicated by studies of infant and perinatal mortality. Scientific evidence has also correlated low birth weight and preterm birth, which are important determinants of perinatal death, with air pollution. However, most of these studies used ambient concentrations measured at monitoring sites, which may not consider differential exposure to pollutants found at elevated concentrations near heavy-traffic roadways.

Objectives

Our goal was to examine the association between traffic-related pollution and perinatal mortality.

Methods

We used the information collected for a case–control study conducted in 14 districts in the City of São Paulo, Brazil, regarding risk factors for perinatal deaths. We geocoded the residential addresses of cases (fetal and early neonatal deaths) and controls (children who survived the 28th day of life) and calculated a distance-weighted traffic density (DWTD) measure considering all roads contained in a buffer surrounding these homes.

Results

Logistic regression revealed a gradient of increasing risk of early neonatal death with higher exposure to traffic-related air pollution. Mothers exposed to the highest quartile of the DWTD compared with those less exposed exhibited approximately 50% increased risk (adjusted odds ratio = 1.47; 95% confidence interval, 0.67–3.19). Associations for fetal mortality were less consistent.

Conclusions

These results suggest that motor vehicle exhaust exposures may be a risk factor for perinatal mortality.     

Concentration–response curve and cumulative effects between ozone and daily mortality: an analysis in Wallonia,Belgium

Many studies have shown an association between ozone and mortality. However, little data is available on the cumulative effects of ozone on health. A time-series analysis using a Poisson regression was used to measure the impact of ozone on non-traumatic mortality in Wallonia over the period 2000–2012. Initially, a single-lag model was tested. Then a distributed-lag non-linear model was used in order to verify the cumulative effects of ozone on mortality. Our study confirms the existence of an association between ozone and mortality. The linear model without threshold shows a higher sensitivity in persons aged 75 and over (ERR = 0.7, 95 % CI: 0.4; 1.0 %) compared to younger people (ages 25–74) (ERR = 0.2, 95 % CI: ? 0.2; 0.6 %). Taking cumulative effects into account, men and women aged 25–74 have an ozone sensitivity equivalent to those over 75.     

Human and animal rabies prevention and control cost in Bhutan, 2001–2008: The cost–benefit of dog rabies elimination

The objective of this study was to estimate the cost of various interventions and to quantify the economic impacts of rabies in Bhutan. Cost–benefit of dog rabies elimination versus human post exposure treatment cost was also assessed. The average direct medical cost of human post-exposure treatment (using rabies vaccine only) was estimated to be Nu. 1615 (US$ 35.65) per 5-dose Essen regimen per patient. The cost would increase to Nu. 2497 (US$ 55.13) and Nu. 19,633 (US$ 433.41) per patient when one dose of either equine rabies immunoglobulin (ERIG) or human rabies immunoglobulin (HRIG) is administered, respectively. The societal cost (direct medical and indirect patient expenses) per patient was estimated to be Nu. 2019 (US$ 45), Nu. 2901 (US$ 64) and Nu. 20,037 (US$ 442) using vaccine only, vaccine with ERIG and vaccine with HRIG, respectively. The average cost per dog vaccination and sterilization were estimated to be Nu. 75 (US$ 1.66) and Nu. 288 (US$ 6.36), respectively. The total direct cost of rabies and various interventions between 2001 and 2008 was estimated to be Nu. 46.95 million (US$ 1.03 million). The direct cost for intensified human PET was estimated to be Nu. 5.85 million (US$ 0.11 million) per year with a cumulated estimated costs of Nu. 35.10 million (US$ 0.70 million) while the cost of mass dog vaccination with at least 70% coverage is estimated to be approximately Nu. 10.31 million (US$ 0.21 million) at the end of 6 years. The combined cost of mass dog vaccination and human PET was estimated to be greater than the cost of human PET alone during the first 2 years of the campaign, and then would be lower than human PET cost alone after the 5th year of the campaign. The total cumulated cost of the combined strategy was estimated to be Nu. 34.14 million (US$ 0.73 million) and would be lower than the cumulated cost of human PET alone (Nu. 35.10 million, US$ 0.77 million) at the end of 6 years. Rabies represents a substantial economic impact to the Bhutanese society. Well-planned and implemented mass dog vaccination would result in elimination of rabies reservoirs in the domestic dog population and would eliminate human rabies cases. It would also reduce the recurrent expenditure on human post-exposure treatment.     

Dietary patterns are associated with depressive symptoms among Chinese adults: a case–control study with propensity score matching

Purpose

Previous studies have indicated that consumption of particular foods or nutrients is associated with depressive symptoms, but little is known about the role of overall dietary patterns in depressive symptoms. We design this case–control study to evaluate the associations between dietary patterns and high depression symptoms in Chinese adults.

Methods

A total of 1351 participants with high depressive symptoms were matched with 1351 controls using the 1:1 ratio propensity score matching method. Dietary intake was assessed using a valid self-administered food frequency questionnaire, and high depressive symptoms were assessed with the Zung Self-Rating Depression Scale, wherein cutoff point of 45 was used as a definition of high depressive symptoms.

Results

Exploratory factor analysis revealed three dietary patterns (vegetables and fruits pattern; sweets pattern; and animal foods pattern) explaining 25.1 % of the total variance. Compared with the participants in the lowest quartile, the participants in the highest quartile of vegetables and fruits pattern, which was defined as a healthy pattern, were associated with reduced odds of high depressive symptoms (OR 0.65, 95 % CI 0.52–0.83, P for trend <0.001) while the sweets pattern (OR 1.33, 95 % CI 1.06–1.66) and the animal foods pattern (OR 1.79, 95 % CI 1.43–2.24, P for trend <0.0001) were associated with increased prevalence of high depressive symptoms, respectively.

Conclusion

The present study adds to the evidence that the sweets pattern and animal foods pattern are positively associated with the prevalence of high depressive symptoms. In contrast, the dietary pattern rich in vegetables, fruits, and soya bean products, but low in animal foods, candied fruits, cakes, ice cream, sugared beverages, and alcoholic drinks is negatively associated with the prevalence of high depressive symptoms.

     

Relation between overweight, diabetes, stress and hypertension: A case–control study in Yarumal – Antioquia, Colombia

Aims: The aim of this study was to assess the association between overweight, diabetes, stress and other postulated risk factors for a high blood pressure, on the risk of hypertension. Methods and Results: This matched case–control study included 228 cases randomly selected in a rural adult population in Yarumal – Antioquia, Colombia. For every case, one control, individually matched by age (± 5 years), sex and residence, was selected from the general population. Conditional logistic regression was used to estimate odds ratios (OR). Obese people (body mass index (BMI) 30 kg/m²) showed an increased OR of hypertension compared to those with a BMI < 25 kg/m², OR: 3.83 [95% confidence interval (CI): 1.83–8.00]. A high level of psychological stress was associated with hypertension (measured on a tension–anxiety scale), OR: 5.02 (95% CI: 2.25–11.19). A positive association was also observed for diabetes although it was of borderline significance, OR: 2.58 (95% CI: 0.88–7.55). Having a family member with hypertension or myocardial infarction was related to a higher risk of hypertension (p < 0.05). Conclusions: This study provides evidence that BMI, stress (feelings of anxiety or tension), and diabetes are independently associated with an increased risk of hypertension in a rural area of Colombia.     

Serum taurine and risk of coronary heart disease: a prospective, nested case–control study

Purpose

Taurine (2-aminoethanesulfonic acid), a molecule obtained from diet, is involved in bile acid conjugation, blood pressure regulation, anti-oxidation and anti-inflammation. We performed the first prospective study of taurine and CHD risk.

Methods

We conducted a case–control study nested in the New York University Women’s Health Study to evaluate the association between circulating taurine levels and risk of coronary heart disease (CHD). Taurine was measured in two yearly pre-diagnostic serum samples of 223 CHD cases and 223 matched controls and averaged for a more reliable measurement of long-term taurine levels.

Results

Mean serum taurine was positively related to age and dietary intake of poultry, niacin, vitamin B1, fiber and iron, and negatively related to dietary intake of saturated fat (all p values ≤0.05). There was no statistically significant association between serum taurine levels and the risk of CHD in the overall study population. The adjusted ORs for CHD in increasing taurine tertiles were 1.0 (reference), 0.85 (95% CI, 0.51–1.40) and 0.66 (0.39–1.13; p for trend = 0.14). There was a significant inverse association between serum taurine and CHD risk among women with high total serum cholesterol (>250 mg/dL) (adjusted OR = 0.39 (0.19–0.83) for the third versus first tertile; p for trend = 0.02) but not among those with low total serum cholesterol (p for interaction = 0.01). The data suggest a possible inverse association of serum taurine with diabetes and hypertension risk.

Conclusions

The findings suggest that high levels of taurine may be protective against CHD among individuals with high serum cholesterol levels.     

Case–control study of environmental risk factors for Parkinson's disease in Belgium

The aetiology of Parkinson's disease (PD) is unknown and said to be multifactorial. We report on a retrospective epidemiological case control study, performed in Flanders during a 3-year period, investigating known and potential environmental risk factors for PD by means of questionnaires. We investigated 423 prevalent patients and 205 spouse-controls. We found familial occurrence in 15% of the patients, a mean age of onset of 58 years, and a clear male preponderance (male/female ratio 1.53). Our results suggest more nulliparity among female PD patients (95% CI: 1.08-5.76). We found a discrete clustering of patients in areas with intensive metallurgic frequently employed in metallurgy than controls (95% CI: 1.04-9.20). Furthermore, patients were clearly more exposed to zinc (95% CI: 1.51-90.90) and toluene (95% CI: 1.03 58.82). Male patients report more prostatectomy-surgery (95% CI: 1.54-17.24).     

Dietary Phytochemical Index and Benign Breast Diseases: A Case–Control Study

Abstract

Background: Dietary phytochemical index (DPI) is an inexpensive method for estimating the amounts of phytochemicals in foods. No study has investigated the association of DPI and benign breast diseases (BBD). Our study aimed to compare DPI in patients with BBD and the control group.

Subjects: This is a case–control study of 115 subjects with BBD and 116 healthy women attending the Iranian Center for Breast Cancer affiliated with Academic Center for Education, Culture and Research. Energy-adjusted DPI was calculated based on data collected from 168-item validated food frequency questionnaire. Sociodemographic data, physical activity, and anthropometric measures such as body weight, height, and waist circumference were determined.

Results: After adjustment for age, estrogen therapy, family history of breast disease, intake of dietary supplement, menopause status, waist circumference and physical activity, the odds ratio (OR) of BBD across the energy-adjusted DPI quartiles decreased significantly (OR = 0.3, 95%CI = 0.12–0.93) (P?trend?=?0.02).

Conclusion: We found that higher DPI score is related to lower BBD OR. This simple method may be used for the improvement of dietary intake to prevent BBD.     

Chronic bronchitis and pesticide exposure: a case–control study in Lebanon

Objective Pesticides are widely used toxics. The objective of the study is to evaluate the odds of exposure to pesticides in chronic bronchitis patients.Methods Using the American Thoracic Society standardized questionnaire confirmed by medical diagnosis of chronic bronchitis, a case–control study was␣performed in Lebanon. Pesticide exposure was estimated and between groups comparison was made.Results The study involved 262 controls and 110 chronic bronchitis outpatient subjects from 10 medical centers. Any exposure to pesticides was associated to chronic bronchitis (OR = 2.46 [1.53–3.94]; p < 10⁻⁴). Occupational use presented the highest association (15.92 [3.50–72.41]; p < 10⁻⁴), followed by regional exposure (3.70 [2.05–6.70]; p < 10⁻⁴). Results were confirmed by multivariate and subgroup analysis.Conclusion Pesticide exposure was associated with chronic bronchitis in Lebanese adults. Pesticides toxicological effects may explain chronic respiratory effects associations found with all exposure types.     

Suspected survivor bias in case–control studies: stratify on survival time and use a negative control

ObjectivesSelection bias in case–control studies occurs when control selection is inappropriate. However, selection bias due to improper case sampling is less well recognized. We describe how to recognize survivor bias (i.e., selection on exposed cases) and illustrate this with an example study.Study Design and SettingA case–control study was used to analyze the effect of statins on major bleedings during treatment with vitamin K antagonists. A total of 110 patients who experienced such bleedings were included 18–1,018 days after the bleeding complication and matched to 220 controls.ResultsA protective association of major bleeding for exposure to statins (odds ratio [OR]: 0.56; 95% confidence interval: 0.29–1.08) was found, which did not become stronger after adjustment for confounding factors. These observations lead us to suspect survivor bias. To identify this bias, results were stratified on time between bleeding event and inclusion, and repeated for a negative control (an exposure not related to survival): blood group non-O. The ORs for exposure to statins increased gradually to 1.37 with shorter time between outcome and inclusion, whereas ORs for the negative control remained constant, confirming our hypothesis.ConclusionWe recommend the presented method to check for overoptimistic results, that is, survivor bias in case–control studies.     

Getting serious about test–retest reliability: a critique of retest research and some recommendations

Purpose

To focus attention on the need for rigorous and carefully designed test–retest reliability assessments for new patient-reported outcomes and to encourage retest researchers to be thoughtful, ambitious, and creative in their retest efforts.

Methods

The paper outlines key challenges that confront retest researchers, calls attention to some limitations in meeting those challenges, and describes some strategies to improve retest research.

Results

Modest retest coefficients are often reported as acceptable, and many important decisions—such as the retest interval—appear not to be evidence-based. Retest assessments are seldom undertaken before a measure has been finalized, which rules out using retest data to select strong, reproducible items.

Conclusions

Strategies for improving retest research include seeking input from patients or experts regarding the stability of the construct to support decisions about the retest interval, analyzing item-level retest data to identify items to revise or discard, establishing a priori standards of acceptability for reliability coefficients, using large, heterogeneous, and representative retest samples and collecting follow-up data to better understand consistent and inconsistent responses over time.     

Acute effects of theanine,caffeine and theanine–caffeine combination on attention

Objective: l-theanine is a constituent of tea which is claimed to enhance cognitive functions. We aimed to determine whether theanine and theanine–caffeine combination have acute positive effects on cognitive and neurophysiological measures of attention, compared to caffeine (a positive control) and a placebo in healthy individuals.

Design: In a placebo-controlled, five-way crossover trial in 20 healthy male volunteers, we compared the effects of l-theanine (200?mg), caffeine (160?mg), their combination, black tea (one cup) and a placebo (distilled water) on cognitive (simple [SVRT] and recognition visual reaction time [RVRT]) and neurophysiological (event-related potentials [ERPs]) measures of attention. We also recorded visual (VEPs) and motor evoked potentials (MEPs) to examine any effects of treatments on peripheral visual and motor conduction, respectively.

Results: Mean RVRT was significantly improved by theanine (P?=?0.019), caffeine (P?=?0.043), and theanine–caffeine combination (P?=?0.001), but not by tea (P?=?0.429) or placebo (P?=?0.822). VEP or MEP latencies or SVRT did not show significant inter-treatment differences. Theanine (P?=?0.001) and caffeine (P?=?0.001) elicited significantly larger mean peak-to-peak N2-P300 ERP amplitudes than the placebo, whereas theanine–caffeine combination elicited a significantly larger mean N2-P300 amplitude than placebo (P?P?=?0.029) or caffeine (P?=?0.005). No significant theanine?×?caffeine interaction was observed for RVRT or N2-P300 amplitude.

Discussion: A dose of theanine equivalent of eight cups of back tea improves cognitive and neurophysiological measures of selective attention, to a degree that is comparable with that of caffeine. Theanine and caffeine seem to have additive effects on attention in high doses.