[Health system interventions assessment in Spain: an approach through the analysis of the time trends and the geographical variability of avoidable mortality between 1986 -2001].

Background: Many studies have proposed Avoidable Mortality (ME) to monitor the performance of health services although its usefulness is limited by the multiplicity of the avoidable mortality lists being used. Time trends from 1986-2001 and the geographical distribution of avoidable mortality by provinces, are presented for Spain.

Methods: An Avoidable Mortality consensus list is being used. It includes avoidable mortality through the intervention of health services (ISAS in Spanish) and through health policy interventions (IPSI in Spanish). Time trends are analyzed adjusting Poisson or Joinpoint regression models and the annual percentages of change (APC) are estimated. Changes in geographical distribution between the first half of the analysed period and the second are tested by means of standard mortality ratios (SMR) and comparative mortality rates (CMR) for each province.

Results: Between 1986 and 2001 avoidable mortality decreased (APC: -1.68; CI: -1.99 and -1.38) slightly more than non-avoidable mortality (APC: -1.28; CI: -1.40 and -1.17). Higher reduction was observed for ISAS mortality (APC: -2.77; CI: -2.89 and -2.65) and an irregular trend for IPSI (between 1986-1990 increase APC: 4.86; CI: 3.32 and 6.41, between 1990-95 stabilization APC: -0.03; CI: -2.32 and 2.31 and finally 1995-2001 decrease APC: -3.57; CI: -4.72 and -2.40).

Conclusions: Avoidable mortality decreased more than non avoidable mortality and important geographical variability can be observed among provinces which should be monitored in order to identify the health services weaknesses. The higher ISAS mortality was observed in southern provinces and the higher IPSI mortality in some areas on the coast. The pattern is somewhat similar for both analyzed periods.