| 1. |
- Westerdahl, J, et al.
(författare)
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Reproducibility of a self-administered questionnaire for assessment of melanoma risk
- 1996
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Ingår i: International Journal of Epidemiology. - 0300-5771. ; 25:2, s. 245-251
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The reproducibility of a self-administered questionnaire on different epidemiological variables was examined in a random sample of a cohort of healthy women from the South Swedish Health Care Region. An identical questionnaire has previously been used for assessment of melanoma risk, in a population-based, matched, case-control study from the same region.METHODS: Repeat questionnaires were completed on two occasions, 1-3 years apart, by 670 randomly selected subjects. In addition, exposure data from a case-control study were used to estimate the effect of misclassification.RESULTS: Overall, there was a fair to good consistency between the answers on the two occasions for the various epidemiological variables. Exposure variables identified as risk factors for melanoma development were reasonably reproducible. The estimated proportion of agreement, A, ranged from 0.74 to 0.92, the average correct classification rate (assuming common sensitivity and specificity), pi, was > or = 0.85 and the kappa coefficient, kappa, ranged between 0.52 and 0.83. However, the question on number of raised naevi on the arm was an exception since it had a lower test-retest reliability (A = 0.62, pi = 0.77, kappa = 0.40). When using data from the case-control study, the effect of the estimated random misclassification was found to only slightly bias odds ratios toward one.CONCLUSION: Our questionnaire, used for assessment for melanoma risk, provided information with fair to good test-retest reliability, and corrected odds ratios were found to be only slightly higher than observed odds ratios.
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| 3. |
- Brandt, L, et al.
(författare)
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Blood transfusion as a risk factor for non-Hodgkin lymphoma
- 1996
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Ingår i: British Journal of Cancer. - 0007-0920. ; 73:9, s. 1148-1151
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Tidskriftsartikel (refereegranskat)abstract
- In a case-control study of 280 out of 426 consecutive patients with a recent diagnosis of non-Hodgkin lymphoma (NHL) and 1827 control subjects, 53 (19%) and 230 (13%) respectively had received blood transfusions 1 year or more before the interview. Using an age- and sex-stratified analysis the odds ratio (OR) for transfusion was 1.74 (95% CI 1.24-2.44). ORs were also determined for transfusions received in the intervals 1-5, 6-15, 16-25 and > or = 26 years before diagnosis. In the interval 6-15 years, the OR for transfusion was 2.83 (95% CI 1.60-4.99) whereas ORs for transfusions received in other intervals were lower and not significantly elevated. Histological diagnoses (Kiel classification) and results of staging procedures were known for 185 patients. For low-grade NHL of nodal B-cell chronic lymphocytic leukaemia (B-CLL) or immunocytoma type, the OR for transfusions was 4.15 (95% CI 1.92-9.01). For low-grade nodal lymphomas of follicle centre cell type and high-grade nodal lymphomas, no relation to transfusions could be demonstrated. For high-grade extranodal lymphoma as sole manifestation, OR for transfusions was 3.27 (95% CI 1.30-8.24). It is concluded that blood transfusion may be a risk factor for NHLs especially those of B-CLL or immunocytoma type and for high-grade extranodal lymphoma.
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