Study Design, Setting, and Participants
The study was conducted among smokers with a primary care provider (PCP) at a community health center in Revere, Massachusetts, belonging to Partners HealthCare System. Partners’ EHR identified adults (aged ≥18 years) who had made an office visit to a PCP in the year before May 2009, had a telephone, and had in the past 5 years the entry of “current smoker” in the health monitoring grid or “smoking” on the problem list. Two cohorts of subjects, DTS1 and DTS2, were drawn sequentially from the population during 1 year (July 2009–June 2010), randomly assigned to receive the DTS program or usual care, and followed for 3 months to assess outcomes.
Recruitment and Randomization
All 19 PCPs participated. Each received a list of their patients identified as smokers by the EHR and excluded those who were nonsmokers or not appropriate to contact for telephone counseling. Those not excluded received a letter from the medical director confirming that they were current smokers and offering the option to decline further study contact. Individuals who were not excluded were randomly assigned to intervention or usual care control groups (1:1 for DTS1; 3:1 for DTS2). Randomization was stratified by PCP.
Intervention group participants were mailed one letter monthly for 3 months beginning in August 2009 (DTS1) or January 2010 (DTS2). Letters, signed by the PCP, encouraged the smoker to quit and offered a free telephone consultation by Partners’ Tobacco Treatment Coordinator (TTC), free nicotine patches, and referral to additional treatment resources. Additionally, in DTS2, the TTC made 2 proactive calls to a randomly selected one third of participants (Intervention Plus group) to try to increase uptake of the offer.
Participants who contacted the TTC received a 15-minute consultation following clinical guidelines.2
She offered a free 4-week supply of 21-mg nicotine patches mailed to their home (refillable once), helped smokers obtain prescriptions for other smoking-cessation medication, used a fax-referral system to connect smokers to free multisession counseling from the Massachusetts Smokers Quitline, and referred to in-person counseling programs. The TTC documented the encounter in the EHR and emailed the smoker’s PCP.
Smokers assigned to usual care received a letter from their PCP advising them to stop smoking, encouraging them to make a visit to discuss quitting, and telling them to expect a telephone call in 3 months.
Baseline characteristics were obtained from the EHR. The primary outcome was the proportion of participants who reported using any tobacco treatment during the 3-month study period, defined as (1) any smoking-cessation counseling contact (with the TTC, Quitline, or in-person counseling) or (2) FDA-approved smoking-cessation pharmacotherapy (nicotine patch, gum, lozenge, inhaler, or nasal spray; bupropion; or varenicline). The secondary outcome was tobacco abstinence, defined as self-reported 7-day and 30-day point-prevalence abstinence at 3-month follow-up. Additional outcomes included use of individual components of tobacco treatment and having made a quit attempt (intentional tobacco abstinence lasting ≥24 hours) in the past 3 months. DTS program response was measured as the percentage of eligible subjects who responded to the offer by contacting the TTC.
Outcomes were assessed by telephone survey (5 call attempts, no incentive for completion) at 3-month follow-up. Due to resource constraints, follow-up in DTS1 was attempted for a randomly selected half of control group participants (n
=98). Response rates were calculated using the American Association for Public Opinion Research response-rate calculation #4.16
Results were examined in 2010 separately by cohort, then pooled for analysis using an intention-to-treat approach that included all eligible randomized subjects, with two exceptions. It excluded control-group subjects for whom follow-up was not attempted (n=97) and individuals who after randomization were found to be ineligible because they were nonsmokers or did not speak English. These individuals were included in a subsequent sensitivity analysis. Subjects with missing follow-up data were classified as smokers and considered not to have used tobacco treatment during the study. Baseline factors between study arms and between survey respondents and nonrespondents were compared, and variables related either to group assignment or to survey response were included as covariates in logistic regression models assessing outcomes.
Personnel and material costs of the intervention, excluding research costs, were tracked prospectively. The analysis took the perspective of a provider organization. Cost effectiveness was calculated as the incremental cost divided by the incremental number of quits in the intervention group. The incremental number of quits is the risk difference for 7-day point-prevalence abstinence at follow-up multiplied by the number of intervention patients.