The initial database literature search resulted in 619 published articles. Additional, 23 studies were found from other source and resulted in 642overall articles. Of these articles, 424 were excluded during the initial assessments based on their title and abstract reading and found to be irrelevant. Of the remaining 218 studies, 119 articles were excluded because of different outcome and unclear results. Finally, 84 papers were excluded as results of eligibility criteria. Then, the remained 15 studies were included in the systematic review and meta-analysis (Fig. 1).
Study characteristics
In this study, a total of 6430 study participants were included from four different regions: Addis Ababa (n=5), Oromia (n=5) and SNNP (n=5). Majority (73%) of included studies were cross-sectional and published between 2010 and September 2019. The sample sizes of included studies ranged from 97 to 817, with the response rate of 78–100%. All studies utilized a validated depression assessment tool. Of this, majority (46%) was used PHQ-9 (n=7) and 40% K-10 (n=6) (Table: 1).
Quality of included studies
The overall quality score of included studies ranged from 4 to 9. Of these, eleven studies had good quality and the remaining four studies had fair quality (Supplementary Table: 1).
Test of heterogeneity, publication bias and subgroup analysis
The tests of heterogeneity demonstrated significant heterogeneity (I2= 96.33% and p <0.001). But, there was no evidence of publication bias from the visual inspection of the funnel plot (Fig. 2) and Egger’s test (P =0.06)]. The results of sensitivity analysis also showed that none of the point estimates was outside of the overall 95% confidence interval confirming that there was no influential study. Thus, in this study, the pooled prevalence of depression based on the 15 studies could be important.
Subgroup analysis demonstrated higher pooled prevalence of depression among studies with longitudinal study design (pooled prevalence = 47% (95% CI: 32%-62%), larger sample size (pooled prevalence = 49% (95% CI: 44%-55%), good quality studies[pooled prevalence = 52% (95% CI: 46%-58%)], publication year 2015-2019 [pooled prevalence = 49% (95% CI: 43%-56%)] and among studies conducted in Oromia. From the study level characteristics of subgroup analysis by study design, sample size, study quality, publication year and study setting were significant, which implies the presence of other characteristics that may contribute for the heterogeneity (Table 2).
Prevalence of depression
The overall pooled prevalence of depression was found to be 46% (95% CI; 40% -53%) (Fig: 2).
Factors associated with depression
Based on this study, factors such as: socio-demographic factors (sex and income), social factors (perceived stigma), behavioral factors (substance use) and clinical factors (extra-pulmonary TB and TB treatment phase) were associated with depression (Table: 3).
Socio-demographic factors and depression: In this study, the pooled effect of four studies (12, 16, 19,32) showed that females were around two times (AOR=1.6;95%, 1.10-2.23) more likely experienced depression as compared to males. Moreover, those TB-patients with low socio-economic status or income (9, 11,14)were three times (AOR=3.0;95%, 1.16-4.92) more likely to have depression symptoms compared with those with high income category.
Social factors and depression: In this study, those participant with history of perceived stigma were more than two times (AOR=2.2;95%, 1.67-6.40) (11, 12, 14, 15, 32) more likely experienced depression compared with those who did not experience perceived stigma.
Behavioral factors and depression: In this study, use of substance such as: alcohol and cigarette (9, 11, 12) were the risk factors for depression with the pooled estimate of 3.2 (AOR=3.2; 95%, 1.80-4.45).
Clinical factors and depression: Clinical factors such as extra pulmonary TB (11, 32) (AOR=2.1; 95% 1.48-2.78) and intensive phase of T-treatment (AOR=1.6; 95%, 1.10-2.09)(11, 12, 14) were also associated with depression.