A cost-minimization study of telemedicine. The case of telemonitored polysomnography to diagnose obstructive sleep apnea syndrome.

Objectives: In a context where sleep laboratories are overwhelmed by a growing demand to diagnose obstructive sleep apnea syndrome (OSAS), efficient substitutive solutions to in-laboratory polysomnography should be found. To compare the effectiveness and costs of home unattended polysomnography (Hpsg) and telemonitored polysomnography (TMpsg), a cost minimization study was performed.

Methods: In a crossover trial, 99 patients underwent on two consecutive nights TMpsg and Hpsg according to a randomized order. A legibility recording criterion was retained to measure effectiveness. A microcosting study of TMpsg and Hpsg was performed. The risks to adopt home strategy or telemonitored strategy, according to different scenario chosen to reach the diagnosis in case of failure of Hpsg or TMpsg, were analyzed.

Results: The recording was considered to be ineffective in 11.2% of TMpsg (95% CI, 4.9-17.4) and in 23.4% (95% CI, 19.12-27.68) of Hpsg. The effectiveness differential was 12.2% (95% CI, 1.8-22.6) (p = .02). Assuming that in case of failure PSGs would be re-realized in the same condition to reach the diagnosis, then TMpsg could be selected if Hc/TMc (cost of Hpsg/cost of TMpsg) > 0.97; Hpsg could be selected if Hc/TMc < 0.76. If 0.76 < or = Hc/TMc < or = 0.97, the choice of TMpsg would be ambiguous. TMc was estimated to be $244, while Hc was $153 (Hc/TMc = 0.63).

Conclusion: Unless some specific geographical situations generate significant transport costs, the implementation of a strategy based on unattended polysomnography at home is cost-saving compared to a telemonitoring strategy.