First, let us consider the idea that home studies are appropriate for all. Masa et al,8 in an elegant study, compared therapeutic decisions based on the results of home studies or in-laboratory polysomnograms in patients with a variety of severities of OSA. They used an interesting design to address whether, in individual patients, the same therapeutic decision was made with data from in-laboratory polysomnograms and from home studies. Each patient had both a home study and laboratory study (order randomized) at baseline and 1 month later. Thus, each subject had four studies: two laboratory studies and two home. Data from these studies, together with clinical information, were given to independent physicians who decided whether to prescribe CPAP or not. Not surprisingly, there was high concordance of decision-making (> 90%) for data from the two in-laboratory studies. However, while in those with severe disease (apnea hypopnea index > 30 events/h), there is similar high concordance between decisions from laboratory and home studies, at more moderate disease (eg, apnea hypopnea index = 20) concordance drops to around 80%. Thus, individuals who would be treated on the basis of a laboratory study would not be based on results of a home study. Data from the study of Masa et al9 were also used to develop an economic analysis of the costs of a purely in-laboratory pathway for diagnosis compared with a purely home pathway and to a hybrid model. Even allowing for repeat in-laboratory studies for patients in the “gray zone” based on home studies, the home study pathway proved cheaper.