Background: The national cervical cancer screening program in Thailand has been successful in
reducing overall burden from this disease. However, evaluation on spatial and temporal scales is
needed to assess the efficacy of this program in smaller regions. Here, we geographically assess incidence
in a province with a uniquely heterogeneous distribution of lifestyle factors associated with
religiosity.
Methods: Cervical cancer cases were extracted from the provincial cancer registry from 1989 to
2013. Age-adjusted incidence rates were calculated using population statistics from the census bureau
and adjusted to the Segi world standard population. Bayesian hierarchical modelling was employed
to spatiotemporally map cervical cancer incidence trends in Songkhla province in 5-year
period.
Results: Overall, the incidence of cervical cancer decreased in Songkhla province. The three districts
with a Muslim population of greater than 70% had consistently lower cervical cancer rates from 1989 to
2013 compared with the rest of the predominantly Buddhist districts. Hotspots of incidence were identi-
fied in Sadao, Hat Yai and the juncture of Mueang Songkhla and Singhanakhon in each 5-year period.
Conclusions: Distinct cervical cancer incidence trends by religion over time indicate differences in
sexual habits, lifestyle and religion-associated culture between Muslims and Buddhists, and suggest
divergent risk factor profiles for these groups. The high incidence rates in Sadao and Hat Yai
is likely explained by the main road to Malaysia, which runs across these two areas and has frequent
commercial sex trade. Female sex workers should be targeted as a vulnerable population for
screening efforts to address this continuing burden of cervical cancer.