The number of specialist outpatient consultations is 319 per lOOOenrolees within SP, for example, compared to 338 and 620 per 1 000 enrolees within IMSS and ISSSTE respectively. While some of these differences may reflect unequal need (such as ISSSTE’s slightly older population), others cannot be justified in this way. The number of prescriptions that could not be fully dispensed by a pharmacist due to lack of stock is 33% within SP compared to 14% within IMSS according to survey data (although the SS institutes’ own figures suggest higher rates of dispensed prescriptions). Both of these figures are amongst the highest in the OECD. Out-of-pocket spending has not fallen significantly across the past decade, despite efforts to achieve universal health coverage through the SP reform.