Effectiveness of three sleep apnea management alternatives

Abstract

Rationale: Home respiratory polygraphy (HRP) may be a cost-effective alternative to polysomnography (PSG) for diagnosis and treatment election in patients with high clinical probability of obstructive sleep apnea (OSA), but there is conflicting evidence on its use for a wider spectrum of patients.

Objectives: To determine the efficacy and cost of OSA management (diagnosis and therapeutic decision making) using (1) PSG for all patients (PSG arm); (2) HRP for all patients (HRP arm); and (3) HRP for a subsample of patients with high clinical probability of being treated with continuous positive airway pressure (CPAP) and PSG for the remainder (elective HRP arm).

Methods: Multicentric study of 366 patients with intermediate-high clinical probability of OSA, randomly subjected to HRP and PSG. We explored the diagnostic and therapeutic decision agreements between the PSG and both HRP arms for several HRP cutoff points and calculated costs for equal diagnostic and/or therapeutic decision efficacy.

Results: For equal diagnostic and therapeutic decision efficacy, PSG arm costs were 18% higher than HRP arm costs and 20% higher than elective HRP arm costs. HRP arm costs tended to be lower than elective HRP arm costs, and both tended to be lower than PSG arm costs if patient costs were omitted.

Conclusion: Home respiratory polygraphy is a less costly alternative than polysomnography for the diagnosis and therapeutic decision making for patients with suspected obstructive sleep apnea. We found no advantage in cost terms, however, in using home respiratory polygraphy for all patients or home respiratory polygraphy for the most symptomatic patients and polysomnography for the rest.

Keywords: Cost efficacy; home respiratory polygraphy; portable monitor; sleep apnea.

Figure 1

General flow chart and cost imputation for the 366 included patients distributed into the three study arms (PSG, HRP, and elective HRP) and in the several decision nodes that incorporated cost imputations (cost imputation nodes). (A) Of the 366 included patients, five were lost without adding costs. In the subsequent 361 patients, the costs from PSG tests were included. Nine patients needed to repeat the PSG with the consequent burden. Finally, 361 cases with valid PSG had no additional costs. (B) Of the 366 included patients, six were lost without adding costs. In the subsequent 360 patients, the costs from HRP tests were included. HRP was repeated 52 times, including the correspondent expenditure from HRP repetitions. Of the 360 patients, 12 with invalid HRP underwent PSG with the subsequent additional costs. Patients with valid HRP (348) presented the following three decision situations: (1) OSA diagnosis agreement was reached in 280 patients; of these, 131 reached therapeutic decision agreement (CPAP or no CPAP) ending the branch without adding costs, and there were 149 patients in the group that had no therapeutic decision agreement (136), false- positive (5) and false-negative results (8) in which the PSG cost was added; (2) no OSA diagnosis agreement was reached for 20 patients who ended the branch without additional cost; and (3) patients with no diagnosis agreement (35) or false-negative results (13) who reached the end of the branch with the included costs of PSG. (C) Of the 366 included patients, 205 were selected to undergo HRP and the subsequent 161 were selected to undergo PSG. With the 205 patients, three were lost without adding costs and HRP was repeated 29 times, with the corresponding expenditure for the HRP repetitions. Of the 205 patients, three with invalid HRP underwent PSG, with the consequent additional cost. Patients with valid HRP (199) presented three decision situations: (1) OSA diagnosis agreement was achieved for 159 patients; of these, therapeutic decision agreement (CPAP or no CPAP) was achieved for 112, ending the branch without additional costs. There were 47 patients in the group who had no therapeutic decision agreement (37), false-positive (6), or false-negative results (4) and had added PSG costs. (2) No OSA diagnosis agreement was reached in 12 patients who ended the branch with no additional costs. (3) Patients with no diagnosis agreement (21) or false-negative results (7) reached the end of the branch, with added costs for PSG. Of the 161 patients referred to PSG, three patients were lost with no additional cost. In the subsequent 158 patients, the costs for the PSG test were included. PSG had to be repeated in three patients, with the consequent burden. Finally, 158 cases with valid PSG reached the end of the branch without additional cost. F+ = false positive; F- = false negative; HRP, home respiratory polygraphy; OSA, obstructive sleep apnea; PSG, polysomnography.

Figure 2

Evolution of the agreement level (100 − sum of the percentages of the true positive and negative results) in the therapeutic decisions between HRP and PSG and the Reference, according to incremental levels of HRP AHI. (A) Home respiratory polygraphy arm. (B) Elective home respiratory polygraphy arm. AHI, apnea-hypopnea index; HRP, home respiratory polygraphy; Reference, agreement between before and after 1 mo by polysomnography.

Figure 3

Percentages of the total costs from the HRP and elective HRP arms and their distribution in three groups (test costs, patients' costs, and costs for equal diagnosis and therapeutic decision efficacy) compared with polysomnography costs, which is considered to be 100%. HRP, home respiratory polygraphy; PSG, polysomnography.