Accounting for diversity in the treatment of suicide and self-injury: A systematic review of the past 50 years of randomized controlled trials

Purpose: Patients receiving treatment for self-injurious thoughts and behaviors (SITBs) have diverse backgrounds, yet it remains unclear exactly who is represented in the current SITB treatment literature. Methods: We conducted a systematic review of the past 50 years of randomized controlled trials (RCTs) testing SITB treatments to evaluate sampling practices and reporting of sample characteristics, as well as inclusion of global populations across the included 525 papers. We also assessed changes over the past five decades in these three domains. Results: SITB RCTs frequently reported age and sex (98.6%-95.1%), less frequently reported race (83.4%-38.6%), socioeconomic status (48.1%-46.1%) and ethnicity (41.9%-8.1%), and rarely reported LGBTQ+ status (3.7%-1.6%). U.S.-based RCTs featured predominantly White, non-Hispanic, and non-LGBTQ+ samples. Most RCTs were conducted in high-income North American or European countries. Sample reporting practices, sample representativeness, and inclusion of global populations modestly and inconsistently improved over time. Conclusions: There has not been substantial improvement in reporting practices, sample representativeness, or inclusion of global populations in SITB RCTs over the past 50 years. Acknowledging who is being studied and representing diverse populations in SITB treatment research is key to connecting research advances with those who may need it most.