Table 5. Main characteristics of studies on reducing user fees and its effects on health service utilization in low- and middle-income countries, according to literature review.

Study	Study setting	Study design	Intervention	Quality assessment	Overall risk of bias
Ojeda et al. (1994)28	Colombia – 4 groups of 3 clinics (1 control, and 3 interventions)	CBA	Decrease of charges for a contraceptive implant	Net prices may be misleading due to inflation; some minor differences between baseline and control groups; statistical significance computed by the reviewers	High
Abdu et al. (2004)31	Sudan – 6 public health centres (2 × 3 interventions) and 2 control ones	CBA	Decrease of user fees in PHC facilities	Important differences between control site and treatment sites (catchment area size, rural/urban, outcome results); limited sample size for women at baseline; inappropriate statistical analysis (and no significance level computed)	High

CBA, controlled “before and after”; PHC, primary health care.