Accuracy of co-morbidity data in patients undergoing abdominal wall hernia repair: a retrospective study.

OBJECTIVES: To determine the baseline accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of routinely collected co-morbidity data in patients undergoing abdominal wall hernia repair. METHODS: All patients aged > 18 who underwent umbilical, para-umbilical, inguinal or incisional hernia repair between 1 January 2015 and 1 November 2016 were identified. All parts of the clinical notes were searched for co-morbidities by two authors independently. The following co-morbidities were considered: hypertension, ischaemic heart disease (IHD), diabetes, asthma, chronic obstructive pulmonary disease (COPD), cerebrovascular disease (CVD), chronic kidney disease (CKD), hypercholesterolemia, obesity and smoking. The co-morbidities data from clinical notes were compared with corresponding data in hospital episode statistics (HES) database to calculate accuracy, sensitivity, specificity, PPV and NPV of HES codes for co-morbidities. To assess the agreement between clinical notes and HES data, we also calculated Cohen's Kappa index value as a more robust measure of agreement. RESULTS: Overall, 346 patients comprising 3460 co-morbidity codes were included in the study. The overall accuracy of HES codes for all co-morbidities was 77% (Kappa: 0.13). When calculated separately for each co-morbidity, the accuracy was 72% (Kappa: 0.113) for hypertension, 82% (Kappa: 0.232) for IHD, 85% (Kappa: 0.203) for diabetes, 86% (Kappa: 0.287) for asthma, 91% (Kappa: 0.339) for COPD, 92% (Kappa: 0.374) for CVD, 94% (Kappa: 0.424) for CKD, 74% (Kappa: 0.074) for hypercholesterolemia, 71% (Kappa: 0.66) for obesity and 24% (Kappa: 0.005) for smoking. The overall sensitivity, specificity, PPV and NPV of HES codes were 9, 100, 100, and 77%, respectively. The results were consistent when individual co-morbidities were analyzed separately. CONCLUSIONS: 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.

Laparoscopic versus open umbilical or paraumbilical hernia repair: a systematic review and meta-analysis.

OBJECTIVES: To compare outcomes of laparoscopic repair to open repair of umbilical and paraumbilical hernias. METHODS: We performed a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards. The review protocol was registered with International Prospective Register of Systematic Reviews (Registration Number: CRD42016052131). We conducted a search of electronic information sources, including MEDLINE; EMBASE; CINAHL; the Cochrane Central Register of Controlled Trials (CENTRAL); the World Health Organization International Clinical Trials Registry; ClinicalTrials.gov; and ISRCTN Register, and bibliographic reference lists to identify all randomised controlled trials (RCTs) and observational studies comparing outcomes of laparoscopic repair to open repair of umbilical and paraumbilical hernias. We used the Cochrane risk of bias tool and the Newcastle-Ottawa scale to assess the risk of bias of RCTs and observational studies, respectively. Random effects models were applied to calculate pooled outcome data. RESULTS: We identified three RCTs and seven retrospective cohort studies, enrolling a total of 16,549 patients. Our analyses indicated that open repair was associated with a higher risk of wound infection [Odds ratio (OR) 2.35, 95% CI 1.23-4.48, P = 0.010], wound dehiscence (OR 4.99, 95% CI 1.12-22.28, P = 0.04) and recurrence (OR 4.06, 95% CI 1.54-10.71, P = 0.005), longer length of hospital stay (MD 26.85, 95% CI 8.15-45.55, P = 0.005) and shorter operative time [Mean difference (MD) - 23.07, 95% CI - 36.78 to - 9.35, P = 0.0010] compared to laparoscopic repair. There was no difference in the risk of haematoma (OR 2.03, 95% CI 0.22-18.73, P = 0.53) or seroma (OR 0.67, 95% CI 0.19-2.32, P = 0.53) between the two groups. CONCLUSIONS: The best available evidence (randomised and non-randomised studies) suggests that laparoscopic repair of umbilical or paraumbilical hernias may be associated with a lower risk of wound infection, wound dehiscence and recurrence rate, shorter length of stay but longer operative time. Results from a limited number of RCTs showed no difference in recurrence rates. The quality of the best available evidence is moderate, and selection bias is the major concern due to non-randomised design in most of the available studies. Therefore, considering the level of available evidence, the most reliable approach for repair of umbilical or paraumbilical hernia should be based on surgeon's experience, clinical setting, patient's age and size, hernia defect size and anatomical characteristics. High quality RCTs are required.