There are various possible explanations for the trend to include more severely ill patients in the intervention groups. First of all, physicians might have a tendency to offer a new technology to more severely ill patients, a phenomenon that is known from other disease areas as “launch bias.” Additionally, asthma-related complications (eg, hospitalization or frequent asthma attacks) could be driving factors. At the same time, negative experiences such as emergency department visits might increase the motivation of patients and caregivers to take part in educational activities. canadian health & care mall
The problem of positive selection could have been avoided by randomization of patients. This was not done for two reasons: First of all, potential candidates with poor asthma control and an urgent need for educational activities could have been prevented from being randomized to one of the two intervention groups. The study investigators had rejected this approach categorically at an initial study conference: no one was ready to accept that severely ill patients would be barred from a scientifically proven intervention such as the SPMP in case of being randomized to a CG.
The second reason for not randomizing patients was study feasibility. If patients without constant access to the Internet had been randomized to the IEP group, patient recruitment numbers would have dropped significantly. Since there is just a limited pool of providers offering a small number of educational courses per year, the recruitment period would have been far too short. The benefit-cost ratio of 0.55 for the SPMP alone is comparable to results previously reported by Clark et al and Scholtz et al for their approaches to educate preselected patient groups. They realized benefit-cost ratios of 0.62 and 0.61, respectively. As to the efficiency of patient education in selected risk groups, our findings are also in line with former studies: for every US dollar spent in educational activities, Lewis et al, Clark et al, and O’Brien reported savings of $2.43, $11.22, and $1.48, respectively. This compares to savings of 1.42€ for every Euro spent (SPMP plus IEP) in patients with moderate persistent or severe persistent asthma and savings of 1.21€ in patients with a prior hospitalization, respectively.