Biomedical subjects

Michael S T Hobbs

Publications and source records attributed to Michael S T Hobbs.

3 recordsLinked to original sources

PubMed2003

Improved methods for estimating incidence from linked hospital morbidity data.

BACKGROUND: Linked hospital morbidity data can be used to estimate the incidence of serious chronic disease. However, incidence rates calculated from first-time hospital admissions tend to be overestimated as a result of the erroneous inclusion of prevalent cases that have had previous hospital admissions prior to the study observation period. To address this problem, we have developed the backcasting method. METHOD: A retrograde survival model was implemented to calculate the level of over-ascertainment of incidence according to the number of years of linked data on which the estimates were based and corresponding correction factors were calculated. The method is illustrated using the example of linked hospital morbidity data on diabetes mellitus and then acute myocardial infarction, which was validated against the Perth MONICA database for cardiovascular disease. RESULTS: Corrected estimates of the incidence of diabetes and acute myocardial infarction were produced. The incidence of diabetes was shown to be lower than in North America in accordance with prevalence estimates, whereas the incidence of acute myocardial infarction was overestimated by approximately 10%. CONCLUSION: A new method is presented for estimating incidence trends in disease from linked hospital morbidity data. The advantages of this method are its ease of use with routinely collected data and the relatively low cost of applying it in comparison with community surveys or maintaining formal disease registers. The method has other applications using linked data, such as the study of trends in first-time health care procedures and pharmaceutical prescriptions.

Databases, Factual↗

PubMed2003

Death rate from ischaemic heart disease in Western Australian psychiatric patients 1980-1998.

BACKGROUND: People with mental illness suffer excess mortality due to physical illnesses. AIMS: To investigate the association between mental illness and ischaemic heart disease (IHD) hospital admissions, revascularisation procedures and deaths. METHOD: A population-based record-linkage study of 210 129 users of mental health services in Western Australia during 1980-1998. IHD mortality rates, hospital admission rates and rates of revascularisation procedures were compared with those of the general population. RESULTS: IHD (not suicide) was the major cause of excess mortality in psychiatric patients. In contrast to the rate in the general population, the IHS mortality rate in psychiatric patients did not diminish over time. There was little difference in hospital admission rates for IHD between psychiatric patients and the general community, but much lower rates of revascularisation procedures with psychiatric patients, particularly in people with psychoses. CONCLUSIONS: People with mental illness do not receive an equitable level of intervention for IHD. More attention to their general medical care is needed.

Australia↗

PubMed2002

Changing methods of imaging the common bile duct in the laparoscopic cholecystectomy era in Western Australia: implications for surgical practice.

OBJECTIVE: To assess changes in the use of endoscopic retrograde cholangiopancreatography (ERCP), intraoperative cholangiography (IOC), and surgical exploration of the common bile duct (CBD) associated with the introduction of laparoscopic cholecystectomy (LC). SUMMARY BACKGROUND DATA: The optimal strategy for dealing with potential stones of the CBD during LC remains controversial. METHODS: The authors conducted a population-based study of all cases of cholecystectomy (20,084) in Western Australia in the periods before, during, and after the introduction of LC (1988-1994). Index admissions were linked to previous or subsequent admissions for ERCP. Factors associated with ERCP were analyzed by multivariate regression models. RESULTS: Between 1988 and 1994, admissions for ERCP almost doubled, whereas the use of IOC decreased from 71% to 51%. Different trends were found for open and laparoscopic procedures. Exploration of the CBD declined because of the infrequent use of this procedure in LC. Preoperative ERCP was significantly more common in older patients and men; the reverse was found for IOC. There was an adjusted 3.5-fold increase in preoperative ERCP both during and after the introduction of LC. The adjusted odds ratios for IOC were 0.48 and 0.52 for these periods. CONCLUSIONS: The introduction of LC was associated with increasing reliance on ERCP to image the CBD and a decrease in the use of IOC. These changes were observed in both LC and open cholecystectomy. They suggest that the use of ERCP before cholecystectomy has partly replaced IOC for visualization of the CBD for suspected stones. Although more than 40% of patients undergoing LC had IOC, surgeons appear to be reluctant to perform surgical exploration of the CBD when stones are present. Savings in terms of both complications and cost can be expected if preoperative ERCPs performed for suspicion of uncomplicated CBD stones are replaced by IOC.

Acute Disease↗