Polysomnography indexes are discordant with quality of life, symptoms, and reaction times in sleep apnea patients

OBJECTIVE: We tested whether polysomnography (PSG) indexes were associated with sleepiness, quality of life, or reaction times at baseline and as outcome measures following surgical or sham treatment for patients with obstructive sleep apnea syndrome (OSAS). STUDY DESIGN AND METHODS: Mild-moderate OSAS subjects were measured before and 8 weeks after surgical or sham treatment in this prospective longitudinal study. Measures included standard PSG indexes, sleepiness, quality of life, and reaction times. Associations were examined with Spearman correlations and multivariate linear regression. RESULTS: Correlations between baseline PSG and non-PSG measures ranged from -0.22 to 0.25 (n, 87 subjects; mean correlation, 0.00 +/- 0.11), with one positive association significant of 56 tested (arousal index and SF36 Mental Component Summary, r, 0.25; P = 0.03). Correlations between change in PSG and non-PSG measures ranged from -0.37 to 0.35 (n, 54 subjects; mean correlation, -0.05 +/- 0.19), with no significant positive association of 56 tested. Regression analyses confirmed these results. CONCLUSIONS: PSG indexes are not consistently associated with sleepiness, quality of life, or reaction time, both at baseline and as outcome measures in patients with mild-moderate OSAS. PSG indexes may not quantify some important aspects of OSAS disease burden or treatment outcome. Clinically important outcomes should be measured directly. EBM RATING: A.