Table 6.
Methods used to control for pre-existing illness in assessment of the association between walking and CVD
| Study | Method |
|---|---|
| GISSI-2 (Italy) (D’Avanzo et al, 1993 (50)) | Exclude subjects with history of Ischemic Heart Disease |
| Whitehall Study (Davey Smith, 2000 (46)) | Excluded men with disease at entry |
| No change to results after excluding deaths in the first 5 and 10 years of follow-up | |
| Atherosclerosis in Communities Study (ARIC) (Evenson et al, 1999 (30)) | -NA- |
| Atherosclerosis in Communities Study (ARIC) (Folsom 1997 (31)) | -NA- |
| Study of Osteoporotic Fractures (Gregg et al, 2003 (44)) | Exclude subjects unable to walk without assistance |
| Adjust for self rated health | |
| No change to results after excluding first 2 years of follow-up | |
| Honolulu Heart Program (Hakim et al, 1998 (36)) | Exclude subjects who are physically incapable |
| No change to results after excluding deaths within first year of follow-up | |
| Honolulu Heart Program (Hakim et al, 1999 (35)) | Exclude subjects incapable of ≥1 hour activity |
| Adjust for physical function score | |
| No change to results after excluding those who reported no walking | |
| Nurses Health Study (Hu et al, 2000 (41)) | -NA- |
| Group Health Cooperative of Puget Sound (LaCroix et al, 1996 (34)) | -Exclude subjects with self-reported heart trouble at baseline, CVD-related |
| prescription drugs or hospitalization in past 12 months | |
| -Adjust for self-reported functional status, health status, chronic disease score | |
| -Secondary analysis found effect in those with and without functional limitations | |
| Women's Health Study (Lee et al, 2001 (32)) | -NA- |
| Harvard Alumni Health Study (Lee et al, 1998 (38)) | -NA- |
| Group Health Cooperative of Puget Sound (GHC) (Lemaitre et al, 1995 (48)) | Adjust for symptoms in month priorto index date |
| King County, WA Residents (Lemurtre et al, 1999 (49)) | Adjust for self-reported health status |
| Exclude subjects with history of heart disease, or reported poor health in the prior year | |
| Nurses Health Study (Manson et al, 1999 (43)) | No change in results after excluding subjects unable to walk |
| Women's Health Initiative Observational Study (Manson et al, 2002 (42)) | WHI Study excluded those who were non-ambulatory |
| Total CVD Outcome: No change in results after excluding events occurring in first year of follow-up, or adjusting for functional status, mental and emotional health | |
| Japan Collaborative Cohort Study for Evaluation of Cancer Risk (Noda et al, 2005 (33)) | Used second-lowest walking category as referent group |
| No change to results after excluding deaths within first 2 years of follow-up | |
| Harvard Alumni Study (Sesso et al, 2000 (39)) | -NA- |
| College Alumni Health Study (Sesso et al, 1999 (40)) | -NA- |
| West Birmingham, UK (Shinton et al, 1993 (47)) | Exclude subjects reporting poor health, or with history of myocardial ischemia or peripheral vascular disease |
| Residents of Rancho Bemardo, CA (Smith et al, 2007 (37)) | Adjust for history of CHD |
| Health Professionals Follow-up Study (Tanasescu et al, 2002 (45)) | Exclude subjects reporting difficulty walking or climbing stairs |