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Mendeley readers
Attention Score in Context
| Title |
An accurate test for homogeneity of odds ratios based on Cochran’s Q-statistic
|
|---|---|
| Published in |
BMC Medical Research Methodology, June 2015
|
| DOI | 10.1186/s12874-015-0034-x |
| Pubmed ID | |
| Authors |
Elena Kulinskaya, Michael B Dollinger |
| Abstract |
A frequently used statistic for testing homogeneity in a meta-analysis of K independent studies is Cochran's Q. For a standard test of homogeneity the Q statistic is referred to a chi-square distribution with K-1 degrees of freedom. For the situation in which the effects of the studies are logarithms of odds ratios, the chi-square distribution is much too conservative for moderate size studies, although it may be asymptotically correct as the individual studies become large. Using a mixture of theoretical results and simulations, we provide formulas to estimate the shape and scale parameters of a gamma distribution to fit the distribution of Q. Simulation studies show that the gamma distribution is a good approximation to the distribution for Q. Use of the gamma distribution instead of the chi-square distribution for Q should eliminate inaccurate inferences in assessing homogeneity in a meta-analysis. (A computer program for implementing this test is provided.) This hypothesis test is competitive with the Breslow-Day test both in accuracy of level and in power. |
X Demographics
The data shown below were collected from the profile of 1 X user who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Canada | 1 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 1 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 50 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United States | 1 | 2% |
| Brazil | 1 | 2% |
| Unknown | 48 | 96% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 11 | 22% |
| Researcher | 7 | 14% |
| Student > Master | 7 | 14% |
| Other | 4 | 8% |
| Unspecified | 3 | 6% |
| Other | 7 | 14% |
| Unknown | 11 | 22% |
| Readers by discipline | Count | As % |
|---|---|---|
| Medicine and Dentistry | 7 | 14% |
| Nursing and Health Professions | 5 | 10% |
| Mathematics | 4 | 8% |
| Environmental Science | 3 | 6% |
| Social Sciences | 3 | 6% |
| Other | 12 | 24% |
| Unknown | 16 | 32% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 29 June 2015.
All research outputs
#18,417,643
of 22,815,414 outputs
Outputs from BMC Medical Research Methodology
#1,738
of 2,012 outputs
Outputs of similar age
#192,361
of 266,628 outputs
Outputs of similar age from BMC Medical Research Methodology
#6
of 7 outputs
Altmetric has tracked 22,815,414 research outputs across all sources so far. This one is in the 11th percentile – i.e., 11% of other outputs scored the same or lower than it.
So far Altmetric has tracked 2,012 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 10.2. This one is in the 6th percentile – i.e., 6% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 266,628 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 16th percentile – i.e., 16% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 7 others from the same source and published within six weeks on either side of this one.