A Randomized Controlled Trial on Office Spirometry in Asthma and COPD in Standard General Practice

Study objectives To evaluate whether office spirometry by general practitioners (GPs) is feasible and may improve the diagnosis of asthma and COPD. Methods A prospective, randomized, comparative trial was planned involving 57 Italian pulmonology centers and 570 GPs who had to enroll consecutive subjects aged 18 to 65 years with symptoms of asthma or COPD without a previous diagnosis. Patients were randomized 1:1 into two groups with an interactive voice responding system: conventional evaluation alone vs conventional evaluation and spirometry. Office spirometry was performed by GPs who were trained by reference specialists using a portable electronic spirometer (Spirobank Office; MIR; Rome, Italy). Diagnosis was confirmed by the reference specialist center in blind fashion. Results Seventy-four GPs complied to the trial. Of 333 patients enrolled, 136 nonrandom violators completed the protocol. Per-protocol analysis showed a concordant diagnosis between GPs and specialists in 78.6% of cases in the conventional evaluation-plus-spirometry group vs 69.2% in the conventional evaluation group (p = 0.35). In the intention-to-treat analysis, the respective percentages of concordant diagnosis were 57.9 and 56.7 (p = 0.87). Conclusions Office spirometry by GPs is feasible, but frequent protocol violation and inadequate sample size did not allow us to prove a significant advantage of office spirometry in improving the diagnosis of asthma and COPD in standard general practice as organized at present in Italy, thus reinforcing the need for close cooperation between GPs and specialists in respiratory medicine.