The mean ± SD number of spirometries in the run-in was 19 ± 19 per GP (range, 0 to 120 per GP). After the run-in period, a total of 429 of the 570 GPs (75%) replied to a questionnaire rating the feasibility and usefulness of spirometry as high in 85%, moderate in 14.5%, and nihil only in 0.5% of cases. Nevertheless, only 104 primary physicians (18%) agreed to enter the randomized trial, while 236 GPs (41.4%) agreed to take part in the observational part of the study. The main reasons for not participating in the randomized trial were, in order of decreasing importance, lack of time, lack of confidence with research trials, and lack of compensation.
In the 9-month study period, 333 patients (mean age, 49.0 ± 15.0 years; 172 female and 159 male patients; data missing for 2 patients) were enrolled. The enrollment did not always respect the 65-year age limit, but this was considered a minor protocol violation and all data were processed independently of an upper age limit. As for smoking habits, 172 subjects were nonsmokers (51.7%), 101 were smokers (30.3%), 43 were ex-smokers (12.9%), and 17 were missing data (5.1%). The prevalence of smoking or a former smoking habit was lowest in asthma patients (19.6% and 11.2%, respectively) and highest in the COPD group (46.4% and 19.6%, respectively). Surprisingly, the percentage of nonsmokers (34%) was higher than expected for COPD. website
Each GP enrolled a median of three patients, with a range of 1 to 5 patients in the first group and 1 to 20 patients in the spirometry group. Eighty-three patients entered the conventional evaluation, and 250 patients entered the conventional-plus-spirome-try group. There were 149 patients who resulted as random violators. The primary causes of the frequent randomization errors were, at a similar frequency, that the GPs did not call the IVRS phone number and performed spirometry on most of the patients with respiratory symptoms, or that they called and then disregarded the patient assignment. Of the 184 nonrandom violators, 65 patients were allocated in the conventional evaluation and 119 patients were in the conventional-plus-spirometry group. Two hundred twenty-four patients completed the evaluation process. In 44 of these cases, the GP did not specify any diagnosis. Figure 1 shows the flow diagram of the actual evaluation of the case series.
Figure 1. Flow diagram showing the number of patients enrolled, randomized, and completing the trial. CE = conventional evaluation.