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Table 2. Studies Rated as Poor Quality1

Study Reasons for poor rating1 Result2
Bull and Jamrozik, 1998 (31) Maintenance of comparison groups in question. Nonrandomized trial design (same providers for control and intervention patients based on days of the week during 3 week recruitment) had high potential for contamination. Fair to poor rates of followup assessments (70% at 1 month, 57% at 6 months, 56% at 12 months). Increased proportion of active intervention patients (40%) at 1 month compared with 31% of control patients (a difference of 9%). Increased proportion of active intervention patients (38%) at 6 months compared with 30% of control patients (a difference of 8%). No difference in the active proportion at 1 year, 36% intervention patients compared with 31% control patients (a difference of 5%).
Calfas et al., 1996 (30) Establishment and maintenance of comparison groups in question. Nonrandomized trial design with intervention physicians selected based on personal interest in physical activity. Suggests that control physicians had less interest in physical activity and may have had lower than expected usual care counseling rates at baseline. Trial lost 17% of intervention physicians and 30% of control physicians during study. Increased proportion of intervention patients (52%) achieved PACE active stage (meets HP) at 4-6 weeks compared with 12% of control patients (a difference of 40%; CI, 28% to 52%).
Elder et al., 1995 (28) High loss to followup. 45% of intervention patients responded at 4 years compared with 44% of control patients. Patients who did not complete the followup assessment were excluded from the analysis. Intervention patients reported increased metabolic rate (432) at 4 years compared with 388 for control patients (P=0.0006).
Graham-Clarke and Oldenburg, 1994 (29) Unclear whether randomization was adequate because a greater proportion of intervention patients were at "intended to change" stage (53% compared with 37% of control patients; a difference of 16%; CI, 13% to 19%). Achieved poor rates of followup assessments (44% at 4 months and 50% at 12 months). Paper didn't give sufficient results to abstract needed results relative to randomization. Not reported based on randomization.
Kreuter et al., 2000 (32) Unclear whether randomization was adequate because no baseline demographic characteristics were provided. The analysis made no mention of an intention-to-treat analysis. Used a new PA tool with no validity analysis reported. Intervention patients who received physician advice to exercise before receiving education materials were more likely to change behavior than patients who received no advice (OR, 1.51; CI, 0.95 to 2.4).

1. These studies were rated poor using the USPSTF quality criteria (18). Poor quality studies have fatal flaws rendering the studies invalid.
2. CI = 95% confidence interval; HP = Healthy People 2010 recommendation: Moderate activity 30 min./5 times/week (or) vigorous activity 20 min./3 times/week; OR = Odds ratio; PA = Physical Activity; PACE = Physician-based Assessment and Counseling on Exercise.

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