Comparison of active and cancer registry-based follow-up for breast cancer in a prospective cohort study.
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The authors compared the relative effectiveness of two distinct follow-up designs in prospective cohort studies--the active approach, based on direct contact with study subjects, and the passive approach, based on record linkages with population-based cancer registries--utilizing available information from the New York University Women's Health Study (WHS) and the New York State Cancer Registry (NYSCR). The analyses were limited to breast cancer cases identified during the period 1985-1992, for which follow-up was considered reasonably complete by both the WHS and the NYSCR. Among 12,947 cohort members who reported a New York State address, 303 pathologically confirmed cases were identified through active follow-up and 284 through record linkage. Sixty-three percent of cancers were identified by both sources, 21% by the WHS only, and 16% by the NYSCR only. The agreement was appreciably better for invasive cancers. The percentage of cases identified only by the NYSCR was increased among subjects whose active follow-up was incomplete, as well as among nonwhites, obese patients, and parous patients. This suggests that relying on either type of follow-up alone may introduce certain biases in evaluating risk factors for breast cancer. Combining both approaches appears to be a better strategy in prospective cohort studies. (+info)
Geographic, demographic, and socioeconomic variations in the investigation and management of coronary heart disease in Scotland.
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OBJECTIVE: To determine whether age, sex, level of deprivation, and area of residence affect the likelihood of investigation and treatment of patients with coronary heart disease. DESIGN, PATIENTS, AND INTERVENTIONS: Routine discharge data were used to identify patients admitted with acute myocardial infarction (AMI) between 1991 and 1993 inclusive. Record linkage provided the proportion undergoing angiography, percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass grafting (CABG) over the following two years. Multiple logistic regression analysis was used to determine whether age, sex, deprivation, and area of residence were independently associated with progression to investigation and revascularisation. SETTING: Mainland Scotland 1991 to 1995 inclusive. MAIN OUTCOME MEASURES: Two year incidence of angiography, PTCA, and CABG. Results-36 838 patients were admitted with AMI. 4831 (13%) underwent angiography, 587 (2%) PTCA, and 1825 (5%) CABG. Women were significantly less likely to undergo angiography (p < 0.001) and CABG (p < 0.001) but more likely to undergo PTCA (p < 0.05). Older patients were less likely to undergo all three procedures (p < 0.001). Socioeconomic deprivation was associated with a reduced likelihood of both angiography and CABG (p < 0.001). There were significant geographic variations in all three modalities (p < 0.001). CONCLUSION: Variations in investigation and management were demonstrated by age, sex, geography, and socioeconomic deprivation. These are unlikely to be accounted for by differences in need; differences in clinical practice are, therefore, likely. (+info)
Natural history of dysplasia of the uterine cervix.
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BACKGROUND: A historical cohort of Toronto (Ontario, Canada) women whose Pap smear histories were recorded at a major cytopathology laboratory provided the opportunity to study progression and regression of cervical dysplasia in an era (1962-1980) during which cervical squamous lesions were managed conservatively. METHODS: Actuarial and Cox's survival analyses were used to estimate the rates and relative risks of progression and regression of mild (cervical intraepithelial neoplasia 1 [CIN1]) and moderate (CIN2) dysplasias. In addition, more than 17,000 women with a history of Pap smears between 1970 and 1980 inclusive and who were diagnosed as having mild, moderate, or severe dysplasia were linked to the Ontario Cancer Registry for the outcome of any subsequent cervical cancers occurring through 1989. RESULTS: Both mild and moderate dysplasias were more likely to regress than to progress. The risk of progression from mild to severe dysplasia or worse was only 1% per year, but the risk of progression from moderate dysplasia was 16% within 2 years and 25% within 5 years. Most of the excess risk of cervical cancer for severe and moderate dysplasias occurred within 2 years of the initial dysplastic smear. After 2 years, in comparison with mild dysplasia, the relative risks for progression from severe or moderate dysplasia to cervical cancer in situ or worse was 4.2 (95% confidence interval [CI] = 3.0-5.7) and 2.5 (95% CI = 2.2-3.0), respectively. CONCLUSION: The risk of progression for moderate dysplasia was intermediate between the risks for mild and severe dysplasia; thus, the moderate category may represent a clinically useful distinction. The majority of untreated mild dysplasias were recorded as regressing to yield a normal smear within 2 years. (+info)
Association between age and survival following major amputation. The Scottish Vascular Audit Group.
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OBJECTIVES: To determine whether age is associated with survival following major amputation and whether this association is independent or simply reflects selection bias in amputation level. DESIGN AND MATERIALS: Computer linkage of routine discharge and death data on the 2759 patients undergoing major amputation in Scotland between 1989 and 1993 for peripheral arterial disease. METHODS: Cox's proportional hazards model and multivariate logistic regression analysis using death as the outcome variable and age, sex, urgency, amputation level and recent arterial reconstructive surgery as predictor variables. RESULTS: Proximal amputation was more common in older patients. Survival was associated with both age (p < 0.001) and amputation level (p < 0.001). Age was an independent predictor of death at 30 days (p < 0.0001), 6 months (p < 0.001), 12 months (p < 0.0001) and 2 years (p < 0.0001) postoperation. CONCLUSIONS: Survival following amputation was poor, with only half the patients alive at 2 years. Above-knee amputation was associated with poorer survival, presumably due to the presence of more severe and widespread disease, and was undertaken more commonly in older patients. However, age remained a predictor of survival after adjustment for amputation level. Higher early mortality suggest that a worse prognosis in elderly patients cannot be attributed wholly to actuarial considerations. (+info)
Prescription of acid-suppressing drugs in relation to endoscopic diagnosis: a record-linkage study.
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BACKGROUND: Although widely used, few data are available on the appropriateness of prescribing of acid-suppressing drugs (ASDs), despite guidelines on the investigation and treatment of dyspeptic patients. METHODS: We created a database of 62 000 endoscopy examinations and record-linked these to a prescribing database. Endoscopic diagnoses were classified into peptic, nonpeptic and others. The H2-antagonists, omeprazole and misoprostol, were studied. RESULTS: 35 000 patients had one or more endoscopies during 1978-93; two-thirds were over 45 years of age at first endoscopy. A quarter of all patients who had been endoscoped had consistently normal examinations. Peptic oesophageal pathology was the commonest positive finding. A quarter of those prescribed ASDs between 1989 and 1993 had been endoscoped between 1978 and 1993. In those with a peptic diagnosis prescribed any ASD, the pathologies found were: oesophageal (42.9%), duodenal (36.3%) and gastro-pyloric (21.3%). Patients prescribed omeprazole were more likely to have undergone endoscopy than those prescribed other ASDs, and they were also more likely to have peptic oesophageal pathology. Long-term prescribing (>56 days per year) occurred in two-thirds of patients prescribed ASDs and 40% had at least one endoscopy. In those prescribed short-term ASDs, 20% had undergone at least one endoscopy. Peptic and nonpeptic endoscopic pathology was associated with increased ASD prescribing, but a normal endoscopy did not reduce prescribing. CONCLUSION: ASD prescribing appeared to be mainly symptom-driven. Positive endoscopic findings increased the prescribing of ASDs, but normal findings did not reduce it. (+info)
Method of linking Medicaid records to birth certificates may affect infant outcome statistics.
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OBJECTIVES: This study assessed how different methods of matching Medicaid records to birth certificates affect Medicaid infant outcome statistics. METHODS: Claims paid by Medicaid for hospitalization of the newborn and for the mother's delivery were matched separately to 1995 North Carolina live birth certificates. RESULTS: Infant mortality and low-birthweight rates were consistently lower when Medicaid was defined by a matching newborn hospitalization record than when results were based on a matching Medicaid delivery record. CONCLUSIONS: Studies of birth outcomes in the Medicaid population may have variable results depending on the method of matching that is used to identify Medicaid births. (+info)
Classification differences and maternal mortality: a European study. MOMS Group. MOthers' Mortality and Severe morbidity.
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OBJECTIVES: To compare the ways maternal deaths are classified in national statistical offices in Europe and to evaluate the ways classification affects published rates. METHODS: Data on pregnancy-associated deaths were collected in 13 European countries. Cases were classified by a European panel of experts into obstetric or non-obstetric causes. An ICD-9 code (International Classification of Diseases) was attributed to each case. These were compared to the codes given in each country. Correction indices were calculated, giving new estimates of maternal mortality rates. SUBJECTS: There were sufficient data to complete reclassification of 359 or 82% of the 437 cases for which data were collected. RESULTS: Compared with the statistical offices, the European panel attributed more deaths to obstetric causes. The overall number of deaths attributed to obstetric causes increased from 229 to 260. This change was substantial in three countries (P < 0.05) where statistical offices appeared to attribute fewer deaths to obstetric causes. In the other countries, no differences were detected. According to official published data, the aggregated maternal mortality rate for participating countries was 7.7 per 100,000 live births, but it increased to 8.7 after classification by the European panel (P < 0.001). CONCLUSION: The classification of pregnancy-associated deaths differs between European countries. These differences in coding contribute to variations in the reported numbers of maternal deaths and consequently affect maternal mortality rates. Differences in classification of death must be taken into account when comparing maternal mortality rates, as well as differences in obstetric care, underreporting of maternal deaths and other factors such as the age distribution of mothers. (+info)
Risk of primary biliary liver cirrhosis in patients with coeliac disease: Danish and Swedish cohort data.
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BACKGROUND: Several case reports, but only a few studies, have examined the coexistence of coeliac disease and primary biliary cirrhosis. AIM: To estimate the risk of primary biliary cirrhosis in two national cohorts of patients with coeliac disease in Denmark and Sweden. METHODS: Through record linkage all Danish patients hospitalised with coeliac disease were followed for possible occurrence of primary biliary cirrhosis from 1 January 1977 until 31 December 1992. All patients hospitalised with coeliac disease in Sweden from 1987 to 1996 were also followed in a separate analysis. RESULTS: A total of 896 patients with coeliac disease were identified in Denmark with a median follow up period of 9.1 years for a total of 8040 person-years at risk. Two cases of primary biliary cirrhosis were observed where 0.07 were expected, giving a standardised incidence ratio of 27.6 (95% confidence interval 2.9 to 133.5). A total of 7735 patients with coeliac disease were identified in Sweden with a median follow up period of 5.1 years for a total of 39 284 person-years at risk. Twenty two people with primary biliary cirrhosis were identified compared with 0.88 expected, giving a standardised incidence ratio of 25.1 (95% confidence interval 15.7 to 37.9). CONCLUSION: Patients with coeliac disease are at increased risk of having primary biliary cirrhosis. (+info)