Objective: To describe methods, recruitment success, and 1-y results of a study evaluating the effectiveness of phone- and mail-based weight-loss interventions in a managed care setting.
Design: Randomized clinical trial with three groups, that is, usual care, mail intervention, and phone intervention.
Subjects: In total, 1801 overweight members of a managed-care organization (MCO).
Measurements: Height, weight, medical status, and weight-loss history were measured at baseline. Participation in intervention activities was monitored for 12 months in the two active treatment groups. Self-reported weight was obtained at 6 and 12 months.
Results: More individuals assigned to mail treatment started it (88%) than did those assigned to phone treatment (69%). However, program completion rates were higher in the phone (36%) than mail (7%) intervention. The mean weight losses were 1.93, 2.38, and 1.47 kg at 6 months in the mail, phone, and usual care groups, respectively. The differences between the phone and usual care groups were statistically significant. The mean weight losses at 12 months did not differ by treatment group (2.28 kg mail, 2.29 kg phone, and 1.92 kg usual care). Greater weight loss was seen in men, older participants, and those with no prior experience in a weight-loss program. Heavier participants and those who reported current treatment for depression lost less weight.
Conclusion: Although mail- and phone-based weight-loss programs can be delivered to large numbers of people in an MCO setting, additional work is needed to enhance their clinical efficacy as well as to assess their costs.