RESUMO
OBJECTIVE: Despite innovations in contraceptive methods, unintended pregnancies remain common. Researchers have examined psychological approaches to decrease unintended pregnancies through contraceptive use. These interventions have involved applying aspects of social cognitive theory, the health belief model and self-determination theory. Research findings on the effects of these psychological approaches show conflicting evidence. The aim of this meta-analysis was to clarify the impact of these psychological interventions on unintended pregnancies DESIGN: Meta-analysis of randomized controlled trials (RCTs) of psychological interventions intended to prevent unwanted pregnancies through an increase in the use of contraceptive methods METHODS: A systematic search of databases and article reference lists led to 26 relevant RCTs with a total of 31,222 participants RESULTS: The odds ratio for pregnancy in the psychological intervention condition = .83, 95% CI [.75, .93]. The results also showed that the longer an intervention's follow-up period was, the less the prevention effect. Quality assessment of included studies indicated that all used a treatment manual and reported attrition. It also showed that most studies reported the reasons for drop-out and assessed the facilitators' adherence to the intervention protocol. The proportion of variability due to chance amongst studies was I2 = 22%. Duval and Tweedie's Trim and Fill showed a difference between the observed and the adjusted values. The adjusted value, representing a conservative estimate of effect size, was OR = .891, 95% CI [.777, .999] CONCLUSIONS: Altogether, these results support the efficacy of psychological interventions aimed at preventing unintended pregnancy through contraception.
