Using drug sales data to evaluate the epidemiology of cardio-metabolic risk factors and their inequality: an ecological study on atorvastatin and total cholesterol in Iran

Statins have been effective medications in lowering serum total cholesterol (TC) concentrations across populations over time. The aim of this study was to estimate national and provincial trends in atorvastatin sales in Iran, to systematically quantify its relationship with socio-economic indicators, and changes in TC level. In this retrospective ecological study, conducted in Iran, we examined trends in atorvastatin sales, the wealth index (WI) as a validly-available socio-economic indicator, and TC level between 2004 and 2011. The main outcome variable was mean atorvastatin sold in defined daily dose per 100,000 people per day (DPD). We analyzed the relationship between WI and DPD and between DPD and mean TC across time and space. At national level, both mean WI and mean DPD showed increasing trend over time, while we observed decreasing trend for TC. Mean WI and DPD in 2011 was nearly 5 and 50 time that of their respective figures in 2004, while the mean TC decreased for nearly 10%. Increases in both WI and DPD had happened in every province, but with different patterns. The maximum and minimum changes in DPD versus WI were seen in Gilan and North Khorasan respectively. A striking increase occurred in the sales for atorvastatin in Iran from 2004-2012 in most provinces examined. The wealthier a province became, the more sales were seen for atorvastatin. TC optimistically decreased from 2005 to 2011 and its decrease was positively correlated with increasing sales for atorvastatin.