The number of respondents analyzed differed according to the measure being examined. For example, we included all respondents in analyzing the effect of visit frequency and the effect of being advised to exercise more (n=1141). However, only those respondents who reported being advised to exercise more were included in the analyses of a physician helping to develop an exercise plan and physician follow-up in supporting exercise behavior (n=402).
To determine whether physician counseling was consistent across BMI categories and income (dichotomized at $25,000), we performed stratified analyses on the multilevel logistic regressions.
TABLE 2
What increased the likelihood of exercise? Regular medical care, a physician-assisted exercise plan, and physician follow-up (n=1141)
PHYSICIAN ENCOUNTERS/COUNSELING | PATIENTS MEETING PHYSICAL ACTIVITY RECOMMENDATIONS | |
---|---|---|
aOR* | 95% CI | |
1. Do you have a doctor whom you see for regular health care? | ||
Yes | 1.54 | 1.04-2.28 |
No | Ref | |
2. In a usual year, how often do you see your doctor? | ||
Once a year or less | 1.41 | 1.02-1.95 |
Twice a year or more | Ref | |
3. Have you been advised within the last year by a doctor to exercise more? | ||
Yes | 0.68 | 0.52-0.90 |
No | Ref | |
Of those advised to exercise more (n=402): 4. Has your doctor helped you to develop a plan to increase exercise? | ||
Yes | 1.93 | 1.19-3.15 |
No | Ref | |
5. Has your doctor followed up with you at subsequent visits to see how you increased exercise? | ||
Yes | 2.84 | 1.78-4.53 |
No | Ref | |
aOR, adjusted odds ratio; CI, confidence interval; Ref, reference group. | ||
*Adjusted for sex, age, educational attainment, and baseline physical activity. |
Results
The final cohort consisted of 1141 adults (TABLE 2). Those who did not respond to the follow-up survey were significantly more likely to be younger (P<.001), have less than a high school education (P<.001), and have an annual household combined income <$25,000 (P<.001). Those completing the follow-up survey were more likely to have a doctor for regular care (P<.001), although they saw their doctor, on average, significantly less per year than nonrespondents (P<.001).
Ninety percent of the cohort sample reported having a doctor whom they saw for regular care. Within the last year, 35% had been advised by their doctor to exercise more. Of those who had been so advised, 34% received help from their physician in developing a plan to increase exercise, and 46% were queried at subsequent visits as to how they were progressing with their exercise program.
After adjusting for age, sex, education, and baseline physical activity, we found that those who had a doctor for regular care were 54% more likely to be physically active than those who reported not having a doctor for regular care (aOR=1.54; 95% CI, 1.04-2.28). If the advising physician also developed a plan with the patient to increase exercise, there was nearly a 2-fold increase in physical activity compared with those who received only advice to exercise more (aOR=1.93; 95% CI, 1.19-3.15). If the physician followed up with the exercise plan at subsequent visits, the likelihood of physical activity increased further (aOR=2.84; 95% CI, 1.78-4.53) compared with those who did not receive follow-up from the physician.
Results of stratified analysis by BMI status are shown in TABLE 3. Individuals at normal weight were significantly more likely to be physically active if they had a physician for regular care (aOR=2.76; 95% CI, 1.49-5.13). Overweight adults (BMI 25-29.9 kg/m2) who had been advised by their physician to exercise more were significantly more likely to attain recommended levels of physical activity if their doctor helped develop an exercise plan than were those given more general advice about exercise (aOR=4.99; 95% CI, 1.69-14.73). Overweight individuals who received further counseling with follow-up inquiries were 5.64 times more likely to be physically active (95% CI, 2.10-15.17). A physician-developed exercise plan did not appreciably improve physical activity in obese adults (BMI ≥30 kg/m2); however, benefit in this group was demonstrated when physicians prescribed and followed up with the exercise plan (aOR=2.13; 95% CI, 1.10-4.12). Stratified analysis by income status provided no clear pattern (data not shown).
TABLE 3
What role does BMI play in patients achieving activity goals? (n=1107)
PHYSICIAN ENCOUNTERS/COUNSELING | PATIENTS MEETING PHYSICAL ACTIVITY RECOMMENDATIONS* (aOR [95% CI]) | ||
---|---|---|---|
NORMAL (BMI<25) | OVERWEIGHT (BMI 25-29.9) | OBESE (BMI ≥30) | |
Has seen a doctor for regular care | 2.76 (1.49-5.13) | 1.08 (0.51-2.29) | 1.34 (0.62-2.91) |
In a usual year, has seen a doctor ≤1 time | 1.98 (1.13-3.47) | 0.95 (0.54-1.68) | 0.95 (0.47-1.92) |
Has been advised to exercise more | 1.02 (0.56-1.85) | 0.75 (0.46-1.25) | 0.77 (0.46-1.31) |
Doctor helped develop a plan to exercise more | 0.69 (0.22-2.18) | 4.99 (1.69-14.73) | 1.76 (0.87-3.56) |
Doctor followed up on plan to exercise more | 2.59 (0.80-8.36) | 5.64 (2.10-15.17) | 2.13 (1.10-4.12) |
aOR, adjusted odds ratio; BMI, body-mass index; CI, confidence interval. | |||
*Adjusted for sex, age, educational attainment, and baseline physical activity. |
Discussion