Process measures in an antenatal smoking cessation trial: another part of the picture

Data on provider and patient compliance can be crucial in understanding the degree of a health education program's effectiveness, as well as in identifying areas where the program requires modification. However, such data are rarely systematically reported in randomized trials. This report assesses the degree to which doctors and midwives complied with intervention protocols in a hospital antenatal smoking cessation trial, and also examines the program's acceptability to patients. Provider compliance was assessed principally via consultation audiotapes and provider-completed checklists. The audiotape analysis identified substantial compliance problems. For example, in relation to six specific smoking-related pregnancy risks, the proportions of Experimental Women informed about each individual risk ranged from 26 to 38% and the proportions receiving counselling items ranged from 52 to 79%. Doctors only informed a minority of Experimental Women of the increased risk of Sudden Infant Death Syndrome (28%) and of the presence of toxic chemicals in tobacco (21%). Comparison of compliance data from audiotapes and provider checklists revealed there was no significant agreement in three of four cases tested. Experimental Patients completed questionnaires to assess recall of smoking advice and to rate 12 program features. Of specific Experimental Program elements, the videotape (85%) received the highest level of positive patient ratings and the lottery (42%) the lowest. The process evaluation indicated that the Experimental Program needed some modification to increase its suitability for routine application. The findings also support the value of including an objective measure of provider compliance.