Association Between Depressive Symptoms or Depression and Health Outcomes for Low Back Pain: a Systematic Review and Meta-analysis.

BACKGROUND: Study results vary on whether depressive symptoms are associated with worse prognosis for low back pain (LBP). We assessed the association between depressive symptoms or depression and health outcomes in persons with LBP. METHODS: We searched MEDLINE, Embase, CINAHL, and PsycINFO from inception to June 2020. Eligible studies were cohort and case-control studies assessing the association between depressive symptoms (questionnaires) or depression (diagnoses) and health outcomes in persons aged ≥16 years with LBP in the absence of major pathology. Reviewers independently screened articles, extracted data, and assessed risk of bias using the Quality in Prognosis Studies tool. We classified exploratory versus confirmatory studies based on phases of prognostic factor investigation. We conducted random-effects meta-analyses and descriptive synthesis where appropriate. RESULTS: Of 13,221 citations screened, we included 62 studies (63,326 participants; 61 exploratory studies, 1 confirmatory study). For acute LBP, depressive symptoms were associated with self-reported disability (descriptive synthesis: 6 studies), worse recovery (descriptive synthesis: 5 studies), and slower traffic injury-related claim closure (1 study), but not pain or work-related outcomes. Depressive symptoms were associated with greater primary healthcare utilization for acute LBP (1 confirmatory study). For chronic LBP, depressive symptoms were associated with higher pain intensity (descriptive synthesis: 9 studies; meta-analysis: 3 studies, 2902 participants, ß=0.11, 95% confidence interval (CI) 0.05-0.17), disability (descriptive synthesis: 6 studies; meta-analysis: 5 studies, 3549 participants, ß=0.16, 95% CI 0.04-0.29), and worse recovery (descriptive synthesis: 2 studies; meta-analysis: 2 studies, 13,263 participants, relative risk (RR)=0.91, 95% CI 0.88-0.95), but not incident chronic widespread pain (1 study). DISCUSSION: Depressive symptoms may be associated with self-reported disability and worse recovery in persons with acute and chronic LBP, and greater primary healthcare utilization for acute LBP. Our review provides high-quality prognostic factor information for LBP. Healthcare delivery that addresses depressive symptoms may improve disability and recovery in persons with LBP. Confirmatory studies are needed to assess the association between depressive symptoms and health outcomes in persons with LBP. PROTOCOL REGISTRATION: PROSPERO database (CRD42019130047).

Association between lead in school drinking water systems and educational outcomes in Ontario, Canada.

PURPOSE: The purpose of this study is to use province-wide lead testing data from school drinking water systems and standardized educational assessments to investigate the association between lead exposure in schools and educational outcomes in Ontario, Canada for 2008-09 to 2015-16 school years. METHODS: Lead testing data were linked to assessment results in reading, writing, and mathematics from Ontario's Education Quality and Accountability Office and school neighborhood characteristics from the Ontario Marginalization Index. Sequential negative binomial models were used to estimate the relative risk of lower Education Quality and Accountability Office achievement in schools with lead exceedances in the preceding year, compared with those without. RESULTS: Between 2008-09 and 2015-16, 78% of schools with Education Quality and Accountability Office scores were linked to lead testing results. In schools with lead exceedances, 8% more students failed to achieve the provincial standard for math (95% confidence interval (CI) = 1.07-1.09), 6% more students failed to achieve the provincial standard for reading (95% CI = 1.05-1.08), and 10% more students failed to achieve the provincial standard for writing (95% CI = 1.08-1.11). Associations of attenuated magnitude persisted after covariate adjustment. CONCLUSIONS: Routinely collected lead testing data from school drinking water systems are associated with educational outcomes in the school-aged population and may present an opportunity for ongoing investigation of childhood lead exposures.