Background:
Many parts of the world, specifically Low and Middle Income Countries (LMICs), have experienced increased smoking prevalence. This portends higher future smoking-related disease prevalence. Because the largest burden of smoking-related diseases is likely to fall among the sub-populations least able to pay for healthcare services, this poses a serious threat to the fight against poverty in LMICs. This study contributes to developing an understanding of the socioeconomic disparities in smoking prevalence and intensity in Namibia, a middle income country in Africa, and the potential association with per capita health-related expenditures.

Methods:
Data come from the 2013 Namibia Demographic and Health Survey. The study focuses on out-patient disease (OPD) costs, inpatient disease (IPD) costs and total out-of-pocket (OOP) payments. Concentration curves and indices are estimated for all three variables as well as for smoking intensity and smoking prevalence. Further, three Tobit regression models are run to examine the associations of the different healthcare costs with smoking intensity.

Results:
The concentration index of smoking prevalence is estimated at -0.05 compared to -0.18 for smoking intensity. In contrast, the concentration index of OPD healthcare costs is estimated at 0.34 compared to 0.65 for IPD healthcare costs reflecting disproportionately higher healthcare costs among the rich. The concentration index of the overall total annual OOP payments is 0.55. Tobit regression analysis, however, does not find any statistically significant relationship between the smoking intensity and the amount spent on healthcare.

Conclusions:
The study finds that both smoking prevalence and intensity are only slightly higher among the poor compared to the rich. This will likely exacerbate the overall disease burden among the poor. Healthcare expenditures, in contrast, are more reflective of the country's income inequality. It is conceivable that as the country's economy grows and income inequality reduces, cigarettes may become affordable which may increase consumption across the wealth quintiles.