Table 1.
PubMed search results of various query terms related to association studies
| Initial Query | Results | Combined Query Results | ||||||
| NOT (odds ratio*) | NOT (relative risk*) | NOT (hazard ratio*) | NOT (risk ratio*) | NOT (case-control) | NOT (cohort*) | NOT (associa*) | ||
| odds ratio* | 67,815 | - | 65,047 | 66,898 | 67,238 | 50,804 | 56,612 | 24,427 |
| relative risk* | 32,280 | 29,512 | - | 31,944 | 31,830 | 27,878 | 24,374 | 14,907 |
| hazard ratio* | 8,927 | 8,110 | 8,591 | - | 8,868 | 8,598 | 5,848 | 3,548 |
| risk ratio* | 3,694 | 3,117 | 3,244 | 3,535 | - | 3,377 | 2,814 | 1,841 |
| case-control | 92,264 | 75,253 | 87,862 | 91,935 | 91,947 | - | 83,109 | 50,155 |
| cohort* | 129,128 | 117,925 | 121,222 | 126,049 | 128,248 | 119,973 | - | 75,875 |
| associa* | 1,591,541 | 1,548,153 | 1,574,168 | 1,586,162 | 1,589,688 | 1,549,432 | 1,538,288 | - |
The search results for various keywords related to association studies in PubMed seldom overlap. The search for 'odds ratio*' in PubMed retrieved 67,815 abstracts when accessed on 30 November 2006. Among these, 65,047 (95.9%), 66,998 (98.7%) and 67,238 (99.2%) abstracts did not contain 'relative risk*', 'hazard ratio*' or 'risk ratio*', respectively. Moreover, 50,804 (74.9%) and 56,612 (83.5%) abstracts did not contain 'case-control' or 'cohort*', respectively. By comparison, 75,253 (81.6%) abstracts out of 92,264 containing 'case-control' and 117,925 (91.3%) abstracts out of 129,128 containing 'cohort*' did not contain 'odds ratio*'.