Factors Associated With Nonattendance at Nonspecialist Outpatient Mental Health Clinics: Systematic Review and Meta-Analysis

OBJECTIVE: To date, no meta-analysis has reported pooled prevalence rates for nonattendance in outpatient mental health settings. This study aimed to derive pooled estimates of nonattendance rates at nonspecialist outpatient mental health clinics and describe the factors associated with nonattendance in this setting. METHODS: From inception until July 2024, the MEDLINE, Embase, and PsycInfo databases were searched for eligible studies. Using a random-effects model, the authors pooled prevalence rates of nonattendance at the first, second, and subsequent appointments and generated pooled proportions with 95% confidence intervals. The factors associated with nonattendance were qualitatively synthesized. RESULTS: =99%, N=3,634) (all p<0.001). Nonattendance was consistently associated with extremes of age, low functioning, forgetfulness, financial difficulties, greater illness severity or aggression, personality or substance use disorders, poor therapeutic alliance, negative attitudes toward illness or treatment, and greater distance from the hospital. CONCLUSIONS: Missed appointments are a common occurrence in outpatient mental health clinics, and nonattendance rates progressively increase with successive appointments. Various patient-, illness-, and service-related factors are associated with nonattendance. These findings emphasize the need to strengthen treatment engagement efforts for service users in general outpatient mental health settings.