Improving the global identification of bipolar spectrum disorders: Meta-analysis of the diagnostic accuracy of checklists.

Shifting definitions and differences in the conceptualization of bipolar disorders have contributed to long diagnostic delays, poor reliability, and inconsistent findings. Rating scales are independent of clinical judgment and offer a reliable way to assess manic symptoms, making them good tools to improve both clinical and research diagnoses of bipolar disorder. However, there are dozens of candidates, with few obvious distinguishing characteristics, making it difficult to select one. Our goal was to metaanalyze the diagnostic accuracy of rating scales designed to identify [hypo]manic symptoms. Additionally, we explored potential moderator variables including global region, translation into a different language, and sample composition. Nearly 4000 articles were identified with searches in PubMed and PsycINFO, yielding 127 effect sizes from 103 studies that met the following inclusion criteria: (a) statistics reported by which a standardized effect size could be calculated, (b) participants age 18 + years, (c) reference diagnoses made by semistructured/structured diagnostic interview, (d) results published in English. Multivariate mixed regression models accounted for multiple effect sizes nested within sample. One hundred twenty-seven effect sizes across 14 rating scales were evaluated. There was significant heterogeneity across effect sizes; Cochran's Q(126 df) = 1622.08, p < .00005, and substantial variance components both within (σ2 = .057) and between samples (σ2 = .253). Four measures performed similarly well and significantly better than some competitors after controlling for design and reporting features. The best rating scales offer an inexpensive, efficient way to improve research and clinical diagnostic processes across diverse populations, and could also complement formal diagnoses for examining secular and cultural trends. (PsycINFO Database Record

Review and Meta-Analysis of Epidemiologic Studies of Adult Bipolar Disorder.

OBJECTIVE: To test whether rates of bipolar disorder (BD) have changed over time or vary across geographic regions after adjusting for design features meta-analyzing epidemiologic studies reporting BD prevalence in adults worldwide. DATA SOURCES: Searches in PubMed and PsycINFO using the terms (epidemiology OR community OR prevalence) AND (mania OR "bipolar disorder" OR cyclothymi*) AND adult and backward searches from published reviews were conducted. STUDY SELECTION: Eighty-five epidemiologic studies published in English from 1980 onward that reported prevalence rates for BD or mania for subjects ≥ 18 years old were included. DATA EXTRACTION: We coded BD prevalence, method of data collection, diagnostic criteria, year of study, country, and quality of study design and data reporting. Meta-regression tested whether sample characteristics influenced prevalence rates using the metafor package in R. RESULTS: Eighty-five effect sizes, from 44 countries, from studies spanning the years 1980-2012, included 67,373 people with BD. Lifetime prevalence for BD spectrum was 1.02% (95% CI, 0.81%-1.29%). Prevalence was moderated by the inclusion of BD not otherwise specified (P = .009) and by geographic region; rates from Africa and Asia were less than half of those from North and South America. Rates did not change significantly over 3 decades after controlling for design features. CONCLUSIONS: The overall prevalence rate is consistent with historical estimates, but rates vary significantly across studies. Differences in methodology contribute to the perception that rates of BD have increased over time. Rates varied markedly by geographic region, even after controlling for all other predictors. Research using consistent definitions and methods may expose specific factors that confer risk for BD.