NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.
Santaguida PL, Balion C, Hunt D, et al. Diagnosis, Prognosis, and Treatment of Impaired Glucose Tolerance and Impaired Fasting Glucose. Rockville (MD): Agency for Healthcare Research and Quality (US); 2005 Sep. (Evidence Reports/Technology Assessments, No. 128.)
This publication is provided for historical reference only and the information may be out of date.
Diagnosis, Prognosis, and Treatment of Impaired Glucose Tolerance and Impaired Fasting Glucose.
Show detailsSection A: Calculation of kappa coefficient and confidence intervals (CI)
The simple kappa coefficient is calculated as:
where
The Variance and CI are calculated as follows:
where
and
Section B: Calculation of annualized relative risk, annualized risk for the exposed (IFG or IGT) and the normal glucose groups
Calculation of relative risk (RR t) at time t would be as follows:
where
= Calculated Risk in Exposed Group at time t (or
i.e. in Male) and calculated as:
= Calculated Risk in
Control Group at time t (or i.e. in Female)
and 
can be calculated as:
is Observed Risk after T period
in Exposed Group
is Observed Risk after T period
in Control Group
thus
where
T= Observed duration of study (0.5 to 18 years).
t= Up to one year study duration.
Section C:
Calculation of 95% confidence intervals (CI) for the unadjusted annualized RR
Where:
Section D:
Calculation and test of heterogeneity (Q) and the pooled estimate of
RR{36574}:
Where k is the number of studies being combined, RR i is
the relative risk estimate in ithStudy,
is the weighted estimator of relative risk, and W i is the weight attached to that study (the reciprocal of the variance of the ith study, varRR i).
Q is approximately distributed as a X 2 distribution with k- 1 degrees of freedom under H 0
Fixed effects model
Random effect model
Further, define
The estimated component of variance due to inter-study variation in effect
size,
, is calculated as:
and
Adjusted weights 
for each of the studies is
calculated as
The mean relative risk estimate of all studies 
can then be computed by:
The variance of this estimate is calculated as:
U.S. Department of Health and Human Services
Mike Leavitt, Secretary
Office of Public Health and Science
Richard H. Carmona, M.D., M.P.H., F.A.C.S., Surgeon General of the United States
Agency for Healthcare Research and Quality
Carolyn M. Clancy, M.D., Director
- Appendix G. Calculations - Diagnosis, Prognosis, and Treatment of Impaired Gluco...Appendix G. Calculations - Diagnosis, Prognosis, and Treatment of Impaired Glucose Tolerance and Impaired Fasting Glucose
Your browsing activity is empty.
Activity recording is turned off.
See more...