Table 3.
A Summary of the Characteristics of Included Reviews
| Review | Search dates | Study design of primary studies | Total person years of follow-up/participants | Follow-up time | Location of primary cohort studies as reported | Average age of participants (years) | Sex | Physical activity measurement | Measure of health outcome investigated | Covariates included in multivariable adjusted estimates | Risk of bias tool used in each review | Assessment of publication bias in each review | Statistical heterogeneity | AMSTAR assessment score for each review |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mammen and Faulkner34 | January 1976 to December 2012 | Prospective cohort studies | Not stated. Harvest plot presents lowest category of study sample size as <1,000 subjects and highest as >10,000 subjects. | Reported: ranged from 1 to 27 years | Majority of studies in North America (n=14) and Europe (n=13). The study SF tables included the following countries: Sweden, Norway, Finland, Australia, Netherlands, U.S. | No age restriction reported. The study SF tables indicated population ages from 11 years to 100 years | Mixed (20 studies), female only (5 studies), male only (4 studies) | Subjective physical activity measures of aerobic activity. Only one study objectively measured physical activity via ergometer cycling | Majority of studies: validated measures such as Center for Epidemiologic Studies Depression Scale (CESD); other studies DSM-IV. More direct measures: via physician diagnosis (n=3); hospital discharge register (n=2); or use of antidepressants (n=1) | Under the study quality assessment, authors indicate the studies that assessed for confounding variables (n=11). In discussion, 3 low quality primary studies are reported as not accounting for BMI and social economic status | Critical Appraisal Skills Programme | Narrative | A harvest plot | Low |
| Schuch et al.19 | Database inception to October 18, 2017 | Prospective cohort studies | n=266,939 | person-years 1,837,794 | Average of 7.4 years | Australia, Norway, Germany, U.S., Iceland, Canada, Ghana, India, Mexico, Russia, South Korea, England, Italy, UK, Netherlands, Sweden, Taiwan, Japan, Denmark, Korea, Spain, | Average age not stated. No age restriction reported. Results table shows age group at baseline as "adults, children, adolescents, older adults." | Mixed: median proportion of males across studies, 47% | Self-report questionnaire, such as the International Physical Activity Questionnaire, single or multiple questions on participation in exercise, sports, or physical activity. Only one study objectively measured physical activity via pedometers | Semi-structured diagnostic instruments or self-reported physician diagnosis of depression | Analysis for adjusted and unadjusted measures conducted separately. In subgroup analyses, adjusted for age and sex, BMI, Smoking, and baseline depressive symptoms | Newcastle-Ottawa scale. | Begg and Mazumdar and Egger tests and corrected for this using the Duval and Tweedie trim and fill method | Q and I2 Scores of 25% (low heterogeneity), 25%–50% (moderate), and >50% (high) |
High |
| McDowell et al.35 | Database inception to June 2018 | Prospective cohort studies | >80,000 unique individuals | Median follow-up, 4.75 years From their results table, least follow-up time= 1 year, longest follow-up time, 16 years |
Europe (n=18), Australia (n=2), North America (n=2), Asia (n=2), | A total of 43.7 (25.6–48.4) years. Two studies covered only children or adolescents | Mixed: median proportion of female participants =54.5% (49%–61%) | Self-report measure assessed at baseline alone (n=18) or as change over time (n=6) | Anxiety symptoms (n=8), a screening level for anxiety symptoms indicative of a disorder (n=10), self-reported diagnosis of anxiety disorder (n=1), and diagnosis of an anxiety disorder (n=5) | Analyses of AORs and unadjusted ORs from cohort studies were run separately. Covariates included in multivariable adjusted estimated not stated by the review authors | Q-Coh | Not reported | Q statistic and I2 | Low |
| Schuch et al.36 | Database inception to October 10, 2018 | Prospective cohort studies | n=75,831 | 357,424 person–years | Median of 3.5 years (IQR=2.0–6.5) | Germany, Australia, UK, Sweden, Korea, U.S., Ireland, Spain, The Netherlands, | Average age not stated. No age restriction reported. Results table shows age group at baseline as "adults, children, adolescents, older adults." | Mixed: median males=50.1% | No study used an objective measure to evaluate physical activity | Structured or semistructured diagnostic instruments or self‐reported physician diagnosis of anxiety disorders (n=10 studies), and cut‐offs of anxiety screening instruments (n=4) | Analysis for adjusted OR and OR were conducted separately. In subgroup analyses, adjusted for age and sex, BMI and smoking, | Newcastle‐Ottawa scale | Begg and Mazumdar and Egger tests and corrected through the Duval and Tweedie trim and fill method | Q and I2 statistic Scores of 25% (low heterogeneity), 25%–50% (moderate), and >50% (high) |
High |
Note: The search was conducted on March 19, 2020. The search terms, algorithm, and identified records are reported in Appendix Table 3 (available online).
AMSTAR, Assessment of Multiple Systematic Reviews; UK, United Kingdom.