Selective citation in the literature on the hygiene hypothesis:A citation analysis on the association between infections and rhinitis

Objective Our objective was to assess the occurrence and determinants of selective citation in scientific publications on Strachan's original hygiene hypothesis. His hypothesis states that lack of exposure to infections in early childhood increases the risk of rhinitis. Setting Web of Science Core Collection. Participants We identified 110 publications in this network, consisting of 5551 potential citations. Primary and secondary outcome measures Whether a citation occurs or not, measured and analysed according to the preregistered protocol. Results We found evidence for citation bias in this field: publications supportive of the hypothesis were cited more often than non-supportive publications (OR adjusted for study design [adjOR] 2.2, 95% CI 1.6 to 3.1), and the same was the case for publications with mixed findings (adjOR 3.1, 95% CI 2.2 to 4.5). Other relevant determinants for citation were type of exposure, specificity, journal impact factor, authority and self-citation. Surprisingly, prospective cohort studies were cited less often than other empirical studies. Conclusions There is clear evidence for selective citation in this research field, and particularly for citation bias

Effectiveness of a preventive coaching intervention for employees at risk for sickness absence due to psychosocial health complaints: Results of a randomized controlled trial

OBJECTIVE: To assess the effectiveness of a preventive coaching intervention on sickness absence due to psychosocial health complaints and on general well being of employees. METHODS: Employees at risk for sickness absence were identified and randomized. The intervention group received the preventive coaching program; the control group received usual care. Primary outcome measure of the trial is sickness absence due to psychosocial health complaints; secondary outcome measures are related to general well being, such as psychological distress, fatigue, and coping. RESULTS: No effect of coaching on self-reported sickness absence due to psychosocial health complaints was found. The intervention group reported statistically significant improved health, declined psychological distress, less burnout, less need for recovery, and an increased satisfaction with life. CONCLUSIONS: This study shows that the coaching intervention primarily has an effect on general well being of employees

Scientific citations favor positive results: a systematic review and meta-analysis

Objectives Citation bias concerns the selective citation of scientific articles based on their results. We brought together all available evidence on citation bias across scientific disciplines and quantified its impact. Study Design and Setting An extensive search strategy was applied to the Web of Science Core Collection and Medline, yielding 52 studies in total. We classified these studies on scientific discipline, selection method, and other variables. We also performed random-effects meta-analyses to pool the effect of positive vs. negative results on subsequent citations. Finally, we checked for other determinants of citation as reported in the citation bias literature. Results Evidence for the occurrence of citation bias was most prominent in the biomedical sciences and least in the natural sciences. Articles with statistically significant results were cited 1.6 (95% confidence interval [CI] 1.3-1.8) times more often than articles with nonsignificant results. Articles in which the authors explicitly conclude to have found support for their hypothesis were cited 2.7 (CI 2.0-3.7) times as often. Article results and journal impact factor were associated with citation more often than any other reported determinant. Conclusion Similar to what we already know on publication bias, also citation bias can lead to an overrepresentation of positive results and unfounded beliefs

A meta-analysis of observational studies identifies predictors of sickness absence

Objective: About one in every three employees seen by their occupational physician is absent from work because of psychosocial health complaints. To implement preventive measures, it is necessary to identify predictors for this type of sickness absence. Study Design and Setting: A meta-analysis was carried out to quantify the association between predictive factors and psychosocial sickness absence and to assess clinical outcomes and heterogeneity. Eligible for inclusion were prospective studies that examined this association and provided sufficient information to estimate summary odds ratios (SORs). Results: Twenty prospective studies were included. Significant SORs for sick leave >3 days were found for being unmarried, 1.37 (95% confidence interval [CI] = 1.15-1.64), experiencing psychosomatic complaints, 1.79 (95% CI = 1.54-2.07), using medication, 3.13 (95% CI = 1.71-5.72), having a burnout, 2.34 (95% CI = 1.59-3.45), suffering from psychological problems, 1.97 (95% CI = 1.37-2.85), having low job control, 1.28 (95% CI = 1.23-1.33), having low decision latitude, 1.33 (95% CI = 1.16-1.56), and experiencing no fairness at work, 1.30 (95% CI = 1.18-1.45). Conclusion: This study shows that predictors of sickness absence can be identified in a homogeneous manner. The results provide leads to public health interventions to successfully improve psychosocial health and to reduce sickness absence