Table 1. Characteristics of included trials.
| Study | Country | Study design | Subject for analysis treatment (n) | Subject for analysis control (n) | Medication duration | Subject description | Indication for medication | Assessment for depression |
|---|---|---|---|---|---|---|---|---|
| Irwig (2012) [9] | USA | Case-control, retrospective study | Finasteride (61) | Control (29) | <1 year (51%), ≥1 year (49%) | Mean age 31.7 years (finasteride) and 26.2 years (control). Finasteride group was taking the medication for at least 3 months and control group was never used finasteride. | Male pattern hair loss | Beck Depression Inventory-II |
| Pietrzyk et al (2015) [14] | Poland | Observation, cross section study | 5-ARI only (134) | AB only (1,918) | <1 year (21.4%), ≥1 year (78.6%) | Mean age 65.8 years. 4,035 men diagnosed with BPH, control group was never used 5-ARI. | BPH | Beck Depression Inventory |
| Unger et al (2016) [15] | USA | Cohort study (prospective study) | Finasteride (6,941) | Placebo (6,994) | At least 7 years | Mean age 63.5 years (finasteride) and 63.6 years (placebo). A total of 18,880 patients from PCPT were randomly assigned to finasteride and placebo for 7 years. And then PCPT was linked to Medicare claims 13,395 patients. | To identify the relationship between finasteride and prostate cancer | ICD-9 diagnostic codes |
| Welk et al (2017) [16] | Canada | Cohort study (retrospective, propensity score matching study) | 5-ARI (89,844) | Control (89,844) | 1.57–1.60 years | Mean age 75 years. It used 7 types of administrative data sources at Ontario province in Canada. And then it matched with a 5-ARI prescription to those without any 5-ARI prescriptions. Control goup is unexposed of 5-ARI. | To identify the relationship between 5-ARI and depression | ICD-9 & 10 diagnostic codes |
| Hagberg et al (2017) [20] | UK | Cohort study (matching for nested case-control study) | 5-ARI only (2,842) | AB only (11,333) | 7.6 (5-ARI only) & 7.7 (AB only) person-years/per 1,000 person-years | A 78.4% of total patients are more than 60 years old who identified 77,732 men with benign prostatic hyperplasia. It was conducted using the UK's Clinical Practice Research Datalink. | BPH | Depression diagnostic code and who received a prescription for an antidepressant |
5-ARI: alpha reductase inhibitor, AB: adrenergic alpha-antagonist, BPH: benign prostatic hyperplasia, PCPT: Prostate Cancer Prevention Trial, ICD: International Classification of Diseases.