After publication of this work , we noted that we inadvertently included the wrong version of Table two. The Charlson scores presented in the table of the published paper did not exclude heart failure (as described in the methods). Therefore all estimates of comorbidity burden are inflated by one point. While this changes the absolute values of the comorbidity burden it does not alter the conclusions of the study or the patterns of comorbidity described.
The correct data are shown in the following revised Table two (Table 1 here):
Table 1. Co-morbidity burden assessed by Charlson Index
The revised text in the results should read:
Patients had a median of 1.0 comorbidity recorded at baseline admission, although the range was wide (0–12, not including heart failure), with some evidence of an increase in comorbidity burden over time Table two (Table 1 here). Re-calculation of the Charlson Index from hospital separation codes at the index admission and all admissions in the previous two years combined did not change the estimates substantially. Across the cohort this had the effect of increasing the mean number of comorbidities per patient by 0.5, with the median number of recorded comorbidities increasing from 1.0 to 2.0.
The pre-publication history for this paper can be accessed here: