Mapping healthcare service utilisation for diabetes and hypertension in Tanzania mainland: bayesian spatial modeling

Diabetes and hypertension pose a growing non-communicable disease (NCD) burden in sub-Saharan Africa. However, in most countries, healthcare service provision remains uneven and there are no comprehensive methods for monitoring service use. We mapped and modeled district-level patient healthcare service utilisation for diabetes and hypertension in mainland Tanzania to identify spatial patterns and socio-demographic correlates using Bayesian spatial models. We analyzed district-level diabetes and hypertension healthcare service utilisation rates collected from health care facilities in 2024. All 184 districts of Tanzania mainland were included. Huge geographic disparities in healthcare service utilisation were observed across different districts. Diabetes and hypertension healthcare service utilisation were consistently highest in urban districts such as Kinondoni, Ilala, Arusha urban, and Iringa urban, and lowest in rural districts such as Namtumbo, Tunduru, Sikonge, and Mlele. Significant spatial clustering was detected for hypertension (Moran's I = 0.173, p-value = 0.003), and weaker but statistically significant clustering for diabetes (Moran's I = 0.099, p-value = 0.025). For hypertension, stronger clustering was observed among females (Moran's I = 0.195, p-value < 0.001). Being literate had a 3% increased rate of healthcare service utilisation for both diabetes [incidence rate ratio (IRR) = 1.03; 95% credible interval (CrI): 1.01-1.05] and hypertension (IRR = 1.03; 95%CrI: 1.01-1.04). Owning a mobile phone showed an increased rate in healthcare service utilisation of 10% (IRR = 1.10, 95%CrI: 1.06-1.14) for diabetes and 6% (IRR = 1.06; 95%CrI: 1.02-1.10) for hypertension. Ownership of television had a 2% increased rate (IRR = 1.02; 95%CrI 1.01-1.05) for diabetes healthcare service utilisation, while owning a radio showed a 3% (IRR = 0.97, 95%CrI: 0.96-0.99) decreased rate in diabetes healthcare service utilisation. Household size showed a 22% (IRR = 0.78; 95%CrI: 0.64-0.94) reduction in hypertension healthcare service utilisation rate. Overall, Tanzania mainland exhibits marked spatial and gender-specific inequalities in diabetes and hypertension healthcare service utilisation. These inequalities are driven by urban development, with urban districts consistently showing higher healthcare service utilisation, while rural districts, particularly those in the southern and western parts of the country, remain underserved. These findings underscore the need for spatially targeted NCD interventions and district-level resource allocation to ensure equitable access to chronic disease care.