A complexity index used to summarized the features of the health institutions included in the survey was developed using the different characteristics included in the institutional form. The index was constructed grading the institutions as high, medium or low complexity level in each of eight different categories that were part of the institutional data collection form. The categories refer to the capacity of the hospital to provide
was selected and institutions having the complete set of services (essential and optional) were classified as high level, while those lacking any of the optional services or resources were classified as medium level institutions. An overall unweighted score was obtained assigning 2 points to high level institutions, 1 point to medium level institutions, and 0 points to low level institutions in each of the abovementioned categories, and adding across the eight categories a maximum of 16 points. The following table presents essential and optional services or resources for each of the 8 categories.