Record linkage as a research tool for office-based medical care.
OBJECTIVE: To explore the feasibility of linking records to study health services and health outcomes for primary care patients. DESIGN: A cohort of patients from the Family Medicine Centre at Mount Sinai Hospital was assembled from the clinic's billing records. Their health numbers were linked to the Ontario Hospital Discharge Database. The pattern of hospital admission rates was investigated using International Classification of Diseases (ICD) codes for primary discharge diagnosis. A pilot case-control study of risk factor management for stroke was nested in the cohort. SETTING: Family medicine clinic based in a teaching hospital. PARTICIPANTS: A cohort of 19,654 Family Medicine Centre patients seen at least once since 1991. MAIN OUTCOME MEASURES: Admission rates by age, sex, and diagnosis. Numbers of admissions for individual patients, time to readmission, and length of stay. Odds ratios for admission for cerebrovascular disease. RESULTS: The 19,654 patients in the cohort had 14,299 discharges from Ontario hospitals in the 4 years from 1992 to 1995, including 3832 discharges following childbirth. Some patients had many discharges: 4816 people accounted for the 10,467 admissions excluding childbirth. Excluding transfers between institutions, there were 4975 readmissions to hospital during the 4 years, 1392 (28%) of them within 28 days of previous discharge. Admissions for mental disorders accounted for the greatest number of days in hospital. The pilot study of risk factor management suggested that acetylsalicylic acid therapy might not be effective for elderly primary care patients with atrial fibrillation and that calcium channel blocker therapy might be less effective than other therapies for preventing cerebrovascular disease in hypertensive primary care patients. CONCLUSIONS: Record linkage combined with data collection by chart review or interview is a useful method for studying the effectiveness of medical care in Canada and might suggest interesting hypotheses for further investigation. (+info)
Do case studies mislead about the nature of reality?
This paper attempts a partial, critical look at the construction and use of case studies in ethics education. It argues that the authors and users of case studies are often insufficiently aware of the literary nature of these artefacts: this may lead to some confusion between fiction and reality. Issues of the nature of the genre, the fictional, story-constructing aspect of case studies, the nature of authorship, and the purposes and uses of case studies as "texts" are outlined and discussed. The paper concludes with some critical questions that can be applied to the construction and use of case studies in the light of the foregoing analysis. (+info)
Do studies of the nature of cases mislead about the reality of cases? A response to Pattison et al.
This article questions whether many are misled by current case studies. Three broad types of style of case study are described. A stark style, based on medical case studies, a fictionalised style in reaction, and a personal statement made in discussion groups by an original protagonist. Only the second type fits Pattison's category. Language remains an important issue, but to be examined as the case is lived in discussion rather than as a potentially reductionist study of the case as text. (+info)
The influence on survival of delay in the presentation and treatment of symptomatic breast cancer.
The aim of this study was to examine the possible influence on survival of delays prior to presentation and/or treatment among women with breast cancer. Duration of symptoms prior to hospital referral was recorded for 2964 women who presented with any stage of breast cancer to Guy's Hospital between 1975 and 1990. Median follow-up is 12.5 years. The impact of delay (defined as having symptoms for 12 or more weeks) on survival was measured from the date of diagnosis and from the date when the patient first noticed symptoms to control for lead-time bias. Thirty-two per cent (942/2964) of patients had symptoms for 12 or more weeks before their first hospital visit and 32% (302/942) of patients with delays of 12 or more weeks had locally advanced or metastatic disease, compared with only 10% (210/2022) of those with delays of less than 12 weeks (P < 0.0001). Survival measured both from the date of diagnosis (P < 0.001) and from the onset of the patient's symptoms (P = 0.003) was worse among women with longer delays. Ten years after the onset of symptoms, survival was 52% for women with delays less than 12 weeks and 47% for those with longer delays. At 20 years the survival rates were 34% and 24% respectively. Furthermore, patients with delays of 12-26 weeks had significantly worse survival rates than those with delays of less than 12 weeks. Multivariate analyses indicated that the adverse impact of delay in presentation on survival was attributable to an association between longer delays and more advanced stage. However, within individual stages, longer delay had no adverse impact on survival. Analyses based on 'total delay (i.e. the interval between a patient first noticing symptoms and starting treatment) yielded very similar results in terms of survival to those based on delay to first hospital visit (delay in presentation). (+info)
Record-linkage for pharmacovigilance in Scotland.
Record-linkage is the linkage of patient-specific information that is stored separately. Recent advances in computerization have meant that record-linkage techniques in medical research are increasingly being used and refined. In particular, they have made a significant contribution to pharmacovigilance, which involves linking drug exposure to outcomes data. In this article, the contribution of record-linkage in Scotland to medical research is described. The two organizations that utilize record-linkage techniques are the Medicines Monitoring Unit (MEMO) of the University of Dundee and the Information and Statistics Division (ISD) of the NHS in Scotland. Pharmacovigilance is MEMO's main concern (using data from the Tayside region of Scotland), while ISD link health care datasets for Scotland for general health care research. The experience of the two groups is now being combined to carry out drug safety studies in the entire population of Scotland. (+info)
Measuring the effects of reminders for outpatient influenza immunizations at the point of clinical opportunity.
OBJECTIVE: To evaluate the influence of computer-based reminders about influenza vaccination on the behavior of individual clinicians at each clinical opportunity. DESIGN: The authors conducted a prospective study of clinicians' influenza vaccination behavior over four years. Approximately one half of the clinicians in an internal medicine clinic used a computer-based patient record system (CPR users) that generated computer-based reminders. The other clinicians used traditional paper records (PR users). MEASUREMENTS: Each nonacute visit by a patient eligible for an influenza vaccination was considered an opportunity for intervention. Patients who had contraindications for vaccination were excluded. Compliance with the guideline was defined as documentation that a clinician ordered the vaccine, counseled the patient about the vaccine, offered the vaccine to a patient who declined it, or verified that the patient had received the vaccine elsewhere. The authors calculated the proportion of opportunities on which each clinician documented action in the CPR and PR user groups. RESULTS: The CPR and PR user groups had different baseline compliance rates (40.1 and 27.9 per cent, respectively; P<0.05). Both rates remained stable during a two-year baseline period (P = 0.34 and P = 0.47, respectively). The compliance rates in the CPR user group increased 78 per cent from baseline (P<0.001), whereas the rates for the PR user group did not change significantly (P = 0.18). CONCLUSIONS: Clinicians who used a CPR with reminders had higher rates of documentation of compliance with influenza-vaccination guidelines than did those who used a paper record. Measurements of individual clinician behavior at the point of each clinical opportunity can provide precise evaluation of interventions that are designed to improve compliance with guidelines. (+info)
Incompleteness and retrieval of case notes in a case note audit of colorectal cancer.
Hospital case notes are a crucial source of data but are subject to two major biases: incompleteness of data and non-retrieval. To assess these biases in relation to colorectal cancer a study was performed of all cases of colorectal cancer listed in the Thames cancer registry in patients resident in one of four districts in South Thames regions with a diagnosis in 1988. Five medical record sites were involved. Retrieval rate for all case notes for districts combined was 80%. In two districts the rates were too high for further investigation; in the other two respectively patient survival and whether treatment was given were positively associated with retrieval. Among the four districts incompleteness of notes ranged from 38% to 62% for staging, 8% to 40% for treatment, and 70% to 25% for diagnostic tests. Information about treatment was missing in 3% to 20%; survival data were omitted in less than 5%. In all districts completeness of case notes was inadequate and in some non-retrieval compounded the problem. Missing data reduce the quality of cancer registry data and potentially undermine interpretation of epidemiological studies and evaluation of care. Further research is warranted into the standards and resourcing of medical records departments and their effects on retrieval and data quality. Structured proformas could be applied across specialties to identify missing items in case notes, to identify areas where standards are required, or to audit notes where standards have already been agreed. A staging protocol to set standards for colorectal cancer has been adopted in one district, and a prospective audit is being established. (+info)
Comparative hospital databases: value for management and quality.
OBJECTIVES: To establish an accurate and reliable comparative database of discharge abstracts and to appraise its value for assessments of quality of care. DESIGN: Retrospective review of case notes by trained research abstractors and comparison with matched information as routinely collected by the hospitals' own information systems. SETTING: Three district general hospitals and two major London teaching hospitals. PATIENTS: The database included 3905 medical and surgical cases and 2082 obstetric cases from 1990 and 1991. MAIN MEASURES: Accessibility of case notes; measures of reliability between reviewers and of validity of case note content; application of high level quality indicators. RESULTS: The existing hospital systems extracted insufficient detail from case notes to conduct clinical comparative analyses for medical and surgical cases. The research abstractors at least doubled the diagnostic codes extracted. Interabstractor agreement of about 70% was obtained for primary diagnosis and assignment to diagnosis related group. These data were sufficient to create a comparative database and apply high level quality indicators designed to flag topics for further study. For obstetric-specific indicators the rates were comparable for abstractors and the hospital information systems, which in each case was a departmentally based system (SMMIS) producing more detailed and accessible data. CONCLUSIONS: Current methods of extracting and coding diagnostic and procedural data from case notes in this sample of hospitals is unsatisfactory: notes were difficult to access and recording is unacceptably incomplete. IMPLICATIONS: Improvements as piloted in this project, are readily available should the NHS, hospital managers, and clinicians see the value of these data in their clinical and managerial activities. (+info)