Our results demonstrated that HES comorbidity codes in patients undergoing colectomy are specific with good positive predictive value; however, they have substandard accuracy, sensitivity, and negative predictive value. Better documentation of comorbidities in admission clerking proforma may help to improve the quality of source documents for coders, which in turn may improve the accuracy of coding.

Our results demonstrated that HES co-morbidity codes in patients undergoing abdominal wall hernia repair are specific with good positive predictive value; however, they have substandard accuracy, sensitivity, and negative predictive value. The presence of a relatively large number of false negative or missed cases in HES database explains our findings. Better documentation of co-morbidities in admission clerking proforma may help to improve the quality of source documents for coders, which in turn may improve the accuracy of coding.