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Attributable Proportion (attributable + proportion)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

A combination of HbA1c, fasting glucose and BMI is effective in screening for individuals at risk of future type 2 diabetes: OGTT is not needed

JOURNAL OF INTERNAL MEDICINE, Issue 3 2006
M. NORBERG
Abstract. Objective., To identify a screening model that predicts high risk of future type 2 diabetes and is useful in clinical practice. Design and methods., Incident case-referent study nested within a population-based health survey. We compared screening models with three risk criteria and calculated sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and attributable proportion. We used fasting plasma glucose (FPG) alone or with an oral glucose tolerance test (OGTT), glycosylated haemoglobin A (HbA1c) (normal range 3.6,5.3%), body mass index (BMI), triglycerides and family history of diabetes (FHD). Setting., Participants in a health survey at all primary care centres (n = 33 336) and subjects with diagnosed type 2 diabetes in primary and hospital care (n = 6088) in Umeå during 1989,2001. Subjects., Each of the 164 subjects who developed clinically diagnosed type 2 diabetes (median time to diagnosis of 5.4 years) and 304 sex- and age-matched referents without diabetes diagnosis. Results., Screening models with at least one criterion present had sensitivities of 0.90,0.96, specificities of 0.43,0.57 and PPVs of 8,9%. Combinations of the criteria, FPG , 6.1 mmol L,1 (capillary plasma), HbA1c , 4.7% and BMI , 27 in men and BMI , 30 in women, had sensitivities, specificities and PPVs of 0.66%, 0.93% and 32%, and 0.52%, 0.97% and 46% respectively. Using FHD as one of three risk criteria showed comparable results. Addition of triglycerides or OGTT did not improve the prediction. Conclusions., The combination of HbA1c, FPG and BMI are effective in screening for individuals at risk of future clinical diagnosis of type 2 diabetes. OGTT or FHD is not necessary. [source]

Gene,environment interaction between the DRB1 shared epitope and smoking in the risk of anti,citrullinated protein antibody,positive rheumatoid arthritis: All alleles are important

ARTHRITIS & RHEUMATISM, Issue 6 2009
Emeli Lundström
Objective An interaction effect for developing rheumatoid arthritis (RA) was previously observed between HLA,DRB1 shared epitope (SE) alleles and smoking. We aimed to further investigate this interaction between distinct SE alleles and smoking regarding the risk of developing RA with and without anti,citrullinated protein antibodies (ACPAs). Methods We used data regarding smoking habits and HLA,DRB1 genotypes from 1,319 patients and 943 controls from the Epidemiological Investigation of Rheumatoid Arthritis, in which 972 patients and 488 controls were SE positive. Subsequently, 759 patients and 328 controls were subtyped for specific alleles within the DRB1*04 group. Odds ratios with 95% confidence intervals (95% CIs) were calculated by means of logistic regression. Interaction was evaluated by calculating attributable proportion due to interaction, with 95% CIs. Results A strong interaction between smoking and SE alleles in the development of ACPA-positive RA was observed for all DRB1*04 SE alleles taken as a group (relative risk [RR] 8.7 [95% CI 5.7,13.1]) and for the *0401 and *0404 alleles (RR 8.9 [95% CI 5.8,13.5]) and the *01 and *10 alleles (RR 4.9 [95% CI 3.0,7.8]) as specific, separate groups, with similar strength of interaction for the different groups (attributable proportion due to interaction 0.4 [95% CI 0.2,0.6], 0.5 [95% CI 0.3,0.7], and 0.6 [95% CI 0.4,0.8], respectively). Conclusion There is a statistically significant interaction between distinct DRB1 SE alleles and smoking in the development of ACPA-positive RA. Interaction occurs with the *04 group as well as the *01/*10 group, demonstrating that regardless of fine specificity, all SE alleles strongly interact with smoking in conferring an increased risk of ACPA-positive RA. [source]

A novel method for evaluation of improved survival trend for common cancer: early detection or improvement of medical care

JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 1 2007
Wei-Chu Chie PhD
Abstract Rationale, aims and objectives, The improvement of survival with time for cancers has been observed worldwide. However, whether and to what extent such an improvement is attributed to early detection or the advance in medical technology is barely addressed. Method, We developed a novel graphic method to calculate attributable proportions related to two factors. This graphic method was first to calculate adjusted survival curve by the application of direct standardized epidemiological method to tumour staging. The crude survival curve was then compared with the adjusted survival curve. Results, Cumulative survival curves of two time epochs, 1989,1993 (period 1) and 1994,1998 (period 2), on six common cancers collected from cancer registry of National Taiwan University between 1989 and 1998, were compared. The attributable proportions due to early detection and medical care were 77% and 23% for breast cancer, 50% and 50% for cervical cancer, 52% and 48% for colorectal cancer, 76% and 24% for gastric cancer, 66% and 34% for liver cancer, and 30% and 70% for prostate cancer respectively. Conclusion, Distinguishing between early detection from advance in medical care associated with the improvement of survival trend using our graphic method has a significant implication for secondary and tertiary prevention of common cancers. [source]