This study assessed the robustness of ethnic and sociocultural determinants of healthcare decision-making autonomy among Hausa, Fulani, and Kanuri women in Northern Nigeria, using complex sample methods to account for the stratified cluster design of the 2024 NDHS. The central finding is that ethnicity and residence are robust determinants of autonomy, persisting after full adjustment for education, wealth, and age. This robustness — the stability of associations across multiple model specifications and covariates — is the principal contribution of the present study and distinguishes it from descriptive cross-tabulations that do not test whether observed differences hold under statistical control. Overall autonomy was severely limited: 72.6% of women reported husband or partner alone decision making, and only 4.9% exercised independent agency. Joint decision making was more common than independent decision making, suggesting that negotiated agency within the household represents a more attainable pathway for female participation than complete independence — a pattern consistent with frameworks that conceptualize empowerment as multidimensional and context-dependent rather than binary [4,7].

Residence was a robust and statistically significant correlate of autonomy (adjusted F = 50.892, p < 0.001). Urban women were substantially more likely to report joint decision making (33.3%) compared with rural women (18.3%), and rural residence was associated with lower adjusted odds of both independent and joint decision making relative to husband-only control. This urban advantage in negotiated agency is consistent with evidence from sub-Saharan Africa suggesting that urban contexts facilitate exposure to health information, broader social networks, and potentially more egalitarian household structures that create space for women’s participation in care-seeking decisions [1]. However, it is important to note that even among urban women in this sample, husband or partner alone decision making remained the majority experience (60.4%), indicating that residential context modifies but does not eliminate the underlying pattern of male-dominated healthcare authority. The rural-urban gradient in autonomy may also partly reflect self-selection processes, whereby women with higher agency are more likely to reside in or migrate to urban areas, which would amplify observed differences without fully representing the causal effect of urbanization itself.

Ethnicity was the most theoretically significant robust correlate identified in this study. After adjustment for all covariates, Hausa and Fulani women had over 60% lower odds of joint decision making compared with Kanuri women (OR: 0.36 and 0.34, respectively), confirming that ethnic identity captures dimensions of household power that conventional socioeconomic indicators do not. This finding is compatible with broader frameworks emphasizing the primacy of gender norms and relational power structures in shaping health behaviours and service uptake [3]. The particularly notable observation is the distinctiveness of the Kanuri/Beriberi pattern: with approximately 41% of Kanuri women reporting joint decision making — nearly double the proportion observed among Hausa and Fulani women — this group exhibits a qualitatively different household dynamic. This difference may reflect the historically distinct social organisation of Kanuri communities in the Lake Chad basin, where certain traditions of spousal consultation in household matters have been documented, or it may reflect differential geographic concentration in Borno State, where local normative environments differ from the broader Northern Nigerian context [5]. Although the Kanuri subsample was considerably smaller (n = 564) than the Hausa (n = 7,087) and Fulani (n = 2,347) subgroups, the magnitude and statistical significance of the ethnic contrasts suggest a genuine socio-cultural differential warranting further qualitative and community-level investigation. From a programmatic standpoint, this ethnic heterogeneity implies that region-wide or ethnicity-blind interventions may be insufficient: strategies to improve women’s healthcare agency must be calibrated to the specific normative landscape of each community.

Education was a statistically significant model effect (Wald F = 3.930, p = 0.001), but its influence followed a gradient rather than a uniform pattern across categories. Women with no formal education had 40% lower odds of joint decision making compared with those with higher education (OR: 0.60), and primary education conferred only marginally better odds (OR: 0.73). Secondary education, however, was not significantly associated with joint decision making (OR: 0.88, CI: 0.71–1.11), suggesting a threshold effect whereby meaningful gains in autonomy may require substantial rather than minimal educational attainment. This is consistent with research indicating that lower levels of schooling may be insufficient to challenge entrenched gender norms in highly traditional settings, and that the relationship between education and autonomy is non-linear in contexts where social structures powerfully constrain individual agency [3,4]. Crucially, wealth status was not a statistically significant predictor after adjustment (Wald F = 1.303, p = 0.273), providing evidence for what this study terms the socio-cultural paradox: the finding that economic resources alone do not confer decision-making authority when gender norms systematically subordinate women’s voice within the household. This paradox has important policy implications, as it suggests that income-generation and poverty-reduction programmes — while valuable in their own right — are unlikely to produce commensurate gains in women’s healthcare autonomy in Northern Nigeria without complementary interventions targeting normative change.

Age was positively and significantly associated with both joint and independent decision making (OR: 1.01 and 1.05, respectively; p < 0.001). Although the per-year effect size is modest, the direction of association is consistent with West African evidence suggesting that older women accumulate social capital within the household over the course of marriage, often through childbearing and extended conjugal tenure, which gradually enhances their bargaining position in domestic decision-making [4]. This implies that interventions targeting younger married women — who face the steepest deficit in healthcare agency — may be particularly important in efforts to reduce maternal and child health inequities in Northern Nigeria.

Several limitations should be considered when interpreting these findings. The cross-sectional design precludes causal inference; observed associations between ethnicity, residence, and autonomy reflect co-occurrence rather than established directional relationships. Healthcare autonomy was operationalized using a single DHS survey item, which, while standard in large-scale demographic research, may not adequately capture the complexity and situational variability of household decision-making processes in practice. Social desirability bias may additionally lead women — particularly in rural and highly patriarchal settings — to under-report their own decision-making participation. Although complex sample procedures were applied throughout, the modest pseudo-R-square values (Nagelkerke R² = 0.062) indicate that a substantial proportion of variation in autonomy remains unexplained, likely attributable to unmeasured factors such as household composition, spousal communication quality, and local community-level normative environments. Future research employing longitudinal designs, qualitative methods, or multilevel modelling with community-level variables would considerably strengthen causal understanding of the pathways through which ethnicity and residence shape women’s healthcare autonomy in Northern Nigeria.