Objective: Attention control (AC) conditions are used to balance nonspecific attention in randomized trials of behavioral interventions. Very little guidance about which behavioral interventions and outcomes merit AC is available in the literature. The primary aim of the present study is to demonstrate a scenario in which use of AC in a behavioral randomized trial was unnecessary and possibly detrimental.
Methods: Exploratory analyses were performed in a randomized controlled trial that tested whether a patient-centered counseling intervention reduced low-density lipoprotein cholesterol levels in 355 participants with peripheral arterial disease, compared with AC and usual care (UC) conditions. The patient-centered counseling intervention was designed to activate participants to ask their physician for lipid-lowering medication and/or increase dose intensity, increase medication adherence, and reduce fat intake. The AC condition involved attention-matched telephone-delivered health education, and the UC condition consisted of an educational pamphlet.
Results: At 12-month follow-up, the mean low-density lipoprotein cholesterol changes were -11.1 and -6.8 mg/dL in the UC and AC conditions, respectively (p=.17). The proportion of participants who increased the use or dose intensity of medication was significantly lower in AC than in UC: 17.5% versus 30.5% (p=.03). No significant difference in other outcomes was observed between AC and UC.
Conclusions: AC has significantly worse medication outcomes, and there is no indication of a therapeutic effect on other end points. Implications for the use of AC in behavioral randomized trials are discussed.
Trial registration: clinicaltrials.gov Identifier: NCT00217919.