Fig. 2

Correlation between Diagnostic Diversity Index, residence and travel time to the closest tertiary institution. a Diagnostic diversity of inpatient cases living in a particular residential area shows a significant inverse association with the travel time to the next tertiary hospital based on all inpatient cases overall ICD-10 codes. Inpatient cases with travel times over 20 min from their homes have a relevant proportional reduction of diagnostic diversity, typically below the mean baseline of 6.9. b Chloropleth of the Swiss national geographical distribution of diagnostic diversity of inpatient cases according to their Medstat-residential area and the location relative to the closest tertiary inpatient facility (Smaller red dots depict the location of the cantonal/regional tertiary institutions, whereas larger dots depict the location of university hospitals). A grey scale was chosen to depict the DDI level according to the overall quartiles of DDI. Regions with DDI higher than the third DDI quartile are depicted in white. White areas tend to co-localize with tertiary inpatient facilities. c Chloropleth of travel times from the individual Medstat-residential area to the next tertiary inpatient facility. A grey-scale color code based on the quartiles of the travel time to the closest tertiary inpatient facility was used. Regions located over 21 min to the closest tertiary institution are represented in dark grey. d The standardized incidence rate of inpatient cases living in a particular residential area diagnosed with orphan diseases in relation to travel time to the next tertiary hospital shows a significant association with a lower incidence rate for orphan diseases in more remote residential areas