Patterns and determinants of formal healthcare utilisation among individuals with and without proxy-identified mental health need in Tanzania: A cross-sectional analysis of the National Panel Survey

Formal healthcare utilisation remains persistently low across sub-Saharan Africa, yet utilisation patterns among individuals with mental health needs are poorly understood in low- and middle-income country contexts. Using data from the fifth wave of the Tanzania National Panel Survey (2020/21), this study examined patterns and determinants of formal healthcare utilisation among individuals aged 15 years and above with and without proxy-identified mental health need. A nationally representative cross-sectional sample of 11,891 individuals with non-missing outcome data was analysed. Proxy-identified mental health need was determined using the Washington Group Short Set item on difficulty remembering or concentrating at the severe threshold, a proxy associated with common mental disorders. The outcome was any formal provider visit in the four weeks prior to the interview, regardless of reason. Survey-weighted logistic regression estimated odds ratios and predicted probabilities within the Andersen Behavioural Model. Missing outcome data affected 505 individuals in a Missing Not At Random pattern; extreme bounds sensitivity analysis assessed implications for subgroup estimates. Overall weighted formal healthcare utilisation was 19.2%. Proxy-identified mental health need was observed in 54 individuals (weighted prevalence 0.45%). Female sex, older age (55 and above), and Southern Highlands zone residence were independently associated with higher utilisation. Household wealth showed a strong dose-response gradient: individuals in the richest quintile had 2.71 times higher adjusted odds than those in the poorest. Proxy-identified mental health need was not significantly associated with utilisation (adjusted odds ratio 1.27; 95% confidence interval: 0.53-3.04; p = 0.588). Extreme bounds analysis indicated that true utilisation could range from 2.0% to 92.7%, confirming subgroup findings are exploratory. Formal healthcare utilisation in Tanzania is strongly patterned by household wealth, sex, age, and geographic zone. Addressing wealth-related barriers and strengthening service availability in lower-utilisation zones should be the priorities for advancing equitable healthcare utilisation in Tanzania.