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Title: Analysis of routine hospital administrative data (including hospital episode statistics) to assess variation in process and outcomes in gastroenterology
Author: Bowering, Katherine
ISNI:       0000 0004 5350 5416
Awarding Body: University of Liverpool
Current Institution: University of Liverpool
Date of Award: 2014
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Background and Aims: To explore outcomes following gastrointestinal endoscopy using a clinical dataset and then routinely collected administrative data linked to death registry data. Predictors of outcome were studied and variations in crude mortality were analysed. Methods: Endoscopy cases from a single tertiary centre were identified retrospectively using a clinical endoscopy database. Sedation levels, type of procedure and demographic data were analysed. Adverse events following the procedures, including mortality were assessed before and after changes in sedation practice were introduced. For subsequent chapters national administrative data in the form of Hospital Episode Statistics (HES) were linked to the Office of National Statistics Death Registry. Data from 2006 – 2008 were analysed. Episodes of care containing codes for therapeutic endoscopic procedures were extracted (Endoscopic retrograde cholangio-pancreatography (ERCP) and percutaneous endoscopic gastrostomy (PEG)). Finally, episodes of care containing new stroke diagnoses were extracted to analyse the use of percutaneous gastrostomies in the stroke population in England. Factors associated with death following endoscopy were identified. Crude and case-mix adjusted mortality were analysed at institutional level. Results: 7,234 endoscopy cases were identified from the endoscopy clinical database. Following changes in sedation practice 7,071 cases were assessed. Significant reductions in sedation doses were achieved but mortality rates did not fall (0.7% in 2004 and 0.8% in 2006 (p=0.5)). 40,938 episodes of care containing ERCP procedures were identified within the HES data. Logistic regression analysis confirmed age, sex, cancer, emergency admission, and non-cancer co-morbidity as independent predictors of 30-day death after ERCP. Adjusted odds ratios for age were 6.2 for ≥85 yrs vs. <55 yrs; male sex 1.2 vs. female; emergency admission 2.0 vs. elective; cancer 8.6 vs. no cancer and non-cancer co-morbidity 1.5 vs. none. Trust volume of ERCP was not found to be a significant factor in post procedure mortality. Funnel plots of trust level mortality rates, both unadjusted and adjusted, showed all trusts lying within 3 standard deviations of the national mean. 10,952 PEG cases were identified. All-cause mortality was 4.2% at 7 days and 14.6% at 30 days. Logistic regression identified age over 85 years, male sex, emergency admission, motor neurone disease and dementia as predictors of death within 30 days of PEG procedure (p<0.03 for all). No correlation for 30-day death versus PEG volume was identified at NHS Trust level (Pearson r=0.04). 1560 emergency stroke admissions that had a new PEG procedure were identified. Admission to Trusts with a high PEG procedure volume was associated with lower 7-day mortality after PEG procedure of 4.3%, compared to 7.8% and 6.8% in low and medium volume Trusts respectively (p=0.045). Although suggestive of a lower threshold for PEG insertion, the 5 Trusts with the highest rate of PEG insertions in stroke patients had a higher mortality at 30 days (3% compared to 0.9% in the other Trusts). Conclusions: Patient factors are the main determinants of outcome following endoscopy. Analyses of clinical and administrative datasets both require significant man-hours to produce results. Assessing disease severity within HES data is unsatisfactory, limiting case-mix adjustment. However, the data have the advantage of allowing consistent methods of analysis across institutions at a national level providing a more real world analysis than smaller or single centre studies.
Supervisor: Bodger, Keith; Pearson, Mike Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: RA Public aspects of medicine