| 1. |
|
|
| 2. |
- Björk, Jonas, et al.
(författare)
-
Variability in diagnostic accuracy can be estimated using simple population weighting.
- 2009
-
Ingår i: Journal of Clinical Epidemiology. - : Elsevier BV. - 1878-5921 .- 0895-4356. ; 62:1, s. 54-57
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Diagnostic accuracy of a quantitative diagnostic test at a given numeric cutoff is dependent on the type of population (e.g., chronic, referrals, or screening) under investigation. Simple weighted averages calculated from a single study sample may be used to assess variability in accuracy in different types of populations. STUDY DESIGN AND SETTING: We evaluated the accuracy of the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation as a diagnostic test to separate stage 1 and 2 chronic kidney disease (>or=60 mL/min per 1.73 m(2)) from stage 3-5 (<60 mL/min per 1.73 m(2) requiring treatment to prevent progression) in a sample of 850 patients referred for determination of glomerular filtration rate (GFR). Using population weighting, we also estimated the accuracy of the MDRD equation when the GFR distribution typically found in screening situations was mimicked. RESULTS: Estimated diagnostic accuracy of the MDRD equation varied substantially for different population types (sensitivity range 82%-97%, specificity 67%-93%; figures include the original MDRD study). CONCLUSIONS: Reports of diagnostic accuracy should include estimates of the variability of diagnostic accuracy, using different real or tentative population distributions. Population weighting is a useful tool for this purpose.
|
|
| 3. |
|
|
| 4. |
- Cederholm, Maria, et al.
(författare)
-
Low agreement was found between pharmacy data and physician reported use of hospital-administered antenatal corticosteroids
- 2007
-
Ingår i: Journal of Clinical Epidemiology. - : Elsevier BV. - 0895-4356 .- 1878-5921. ; 60:5, s. 512-517
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To evaluate physicians' recall accuracy on starting year of routine use of antenatal corticosteroids (ACS) to women facing imminent preterm delivery. Study Design and Setting: Starting year of routine treatment with ACS was evaluated by a questionnaire mailed to all 52 Swedish maternity wards. The information was compared with that obtained from a telephone interview with physicians involved in the introduction of routine ACS and with pharmacy data. From pharmacy data, routine use of ACS was defined as >= 20 mg betamethasone or dexamethasone purchased per maternity ward, year, and preterm delivery. Results: 24 hospitals with >= 10 preterm deliveries/year, having started ACS 1976-1997 and with information from questionnaire, interview, and pharmacy data were included in the analyses. There was fair agreement (kappa = 0.38, P < 0.001) on starting year between questionnaires and telephone interviews with physicians and slight agreement (kappa = 0.06, P = 0.098) between questionnaires and pharmacy data. Three hospitals had complete agreement on starting year according to questionnaire, telephone interview, and pharmacy data. Conclusion: Agreement between information obtained from questionnaires, telephone interviews with physicians, and pharmacy data on use of ACS was low. Physician reported past drug use needs to be validated and pharmacy data can be useful for such purpose.
|
|
| 5. |
- Fransson, Eleonor, et al.
(författare)
-
Indications of recall bias found in a retrospective study of physical activity and myocardial infarction
- 2008
-
Ingår i: Journal of Clinical Epidemiology. - : Elsevier BV. - 0895-4356 .- 1878-5921. ; 61:8, s. 840-847
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To evaluate the presence of recall bias in retrospective studies of physical activity and myocardial infarction. Study Design and Setting: In 2005, seventy-eight cases who had suffered from a myocardial infarction and 243 control subjects, who had previously participated in the Swedish WOLF (Work, Lipids, and Fibrinogen) study, were asked about their physical activity level during 1990-2005. The answers about recalled past leisure time, occupational, and household physical activity level were compared with physical activity level as reported at the baseline examination of the WOLF study in 1992-1998. Results: The proportion who recalled the same activity level as originally reported ranged from 69% to 96% (cases) and 69% to 89% (controls), and the kappa values ranged from 0.30 to 0.91 (cases) and 0.46 to 0.59 (controls), with the exception of perceived physical workload in household work, which showed low agreement between the originally stated and later recalled activity levels. Some differences were found between cases and controls regarding recall of past occupational activity, indicating the presence of recall bias in this domain of physical activity. Conclusion: We cannot preclude the existence of recall bias when using retrospectively recalled information about occupational physical activity in studies of physical activity and myocardial infarction.
|
|
| 6. |
- Gedeborg, Rolf, et al.
(författare)
-
Diagnosis-dependent misclassification of infections using administrative data variably affected incidence and mortality estimates in ICU patients
- 2007
-
Ingår i: Journal of Clinical Epidemiology. - : Elsevier BV. - 0895-4356 .- 1878-5921. ; 60:2, s. 155-162
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine the accuracy of hospital discharge diagnoses in identifying severe infections among intensive care unit (ICU) patients, and estimate the impact of misclassification on incidence and 1-year mortality. STUDY DESIGN AND SETTING: Sepsis, pneumonia, and central nervous system (CNS) infections among 7,615 ICU admissions were identified using ICD-9 and ICD-10 diagnoses from the Swedish hospital discharge register (HDR). Sensitivity, specificity, and likelihood ratios were calculated using ICU database diagnoses as reference standard, with inclusion in sepsis trials (IST) as secondary reference for sepsis. RESULTS: CNS infections were accurately captured (sensitivity 95.4% [confidence interval (CI)=86.8-100] and specificity 99.6% [CI=99.4-99.8]). Community-acquired sepsis (sensitivity 51.1% [CI=41.0-61.2] and specificity 99.4% [CI=99.2-99.6]) and primary pneumonia (sensitivity 38.2% [CI=31.2-45.2] and specificity 98.6% [CI=98.2-99.0]) were more accurately detected than sepsis and pneumonia in general. One-year mortality was accurately estimated for primary pneumonia but underestimated for community-acquired sepsis. However, there were only small differences in sensitivity and specificity between HDR and ICU data in the ability to identify IST. ICD-9 appeared more accurate for sepsis, whereas ICD-10 was more accurate for pneumonia. CONCLUSION: Accuracy of hospital discharge diagnoses varied depending on diagnosis and case definition. The pattern of misclassification makes estimates of relative risk more accurate than estimates of absolute risk.
|
|
| 7. |
|
|
| 8. |
- Johansson, Lars Age, et al.
(författare)
-
Methodology of studies evaluating death certificate accuracy were flawed.
- 2006
-
Ingår i: Journal of Clinical Epidemiology. - : Elsevier BV. - 0895-4356 .- 1878-5921. ; 59:2, s. 125-31
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND OBJECTIVE: Statistics on causes of death are important for epidemiologic research. Studies that evaluate the source data often give conflicting results, which raise questions about comparability and validity of methods. METHODS: For 44 recent evaluation studies we examined the methods employed and assessed the reproducibility. RESULTS: Thirty studies stated who reviewed the source data. Six studies reported reliability tests. Twelve studies included all causes of death, but none specified criteria for identifying the underlying cause when several, etiologically independent conditions were present. We assessed these as not reproducible. Of 32 studies that focussed on a specific condition, 21 provided diagnostic criteria such that the verification of the focal diagnosis is reproducible. Of 16 that discussed the difference between dying "with" and "from" a condition, eight described how competing causes had been handled. For these eight, the selection of a principal cause is reproducible, but in three the selection strategy conflicts with the international instructions issued by the World Health Organization. CONCLUSION: Methods and criteria are often insufficiently described. When described, they sometimes disagree with the international standard. Explicit descriptions of methods and criteria would contribute to methodologic improvement and would allow readers to assess the generalizability of the conclusions.
|
|
| 9. |
- Johansson, Lars Age, et al.
(författare)
-
Unexplained differences between hospital and mortality data indicated mistakes in death certification : an investigation of 1,094 deaths in Sweden during 1995
- 2009
-
Ingår i: Journal of Clinical Epidemiology. - : Elsevier BV. - 0895-4356 .- 1878-5921. ; 62:11, s. 1202-1209
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Mortality statistics are important for epidemiological research. We examine if discrepancies between death certificate (DC) and hospital discharge condition (HDC) indicate certification errors. STUDY DESIGN AND SETTING: From 39,872 hospital deaths in Sweden in 1995, we randomly selected 600 "cases," where DC and HDC were incompatible, and 600 compatible "controls," matched on sex, age, and underlying cause of death. We obtained case summaries for 1,094 (91%) of these. Using a structured protocol, we assessed the accuracy of DCs. RESULTS: Regression analysis indicated diagnostic group and "case" or "control" as the variables that most affected the accuracy. Malignant neoplasm "controls" had the highest accuracy (92%), and benign and unspecified tumor "cases," the lowest (20%). For all diagnostic groups except one, compatible "controls" had better accuracy than incompatible "cases." The exception, chronic obstructive lung disease, had low accuracy for both "cases" (54%) and "controls" (52%). CONCLUSION: Incompatibility between DC and HDC indicates a greater risk of certification errors. For some diagnostic groups, however, DCs are often inaccurate even when DC and HDC are compatible. By requesting additional information on incompatible cases and all deaths in high-risk diagnostic groups, producers of mortality statistics could improve the accuracy of the statistics.
|
|
| 10. |
|
|
