Table 4.

Outcome of reduced sleep efficiency (≤88% on actigraphy)^*

	Model 1	Model 2	Model 3
1 yr prior	n = 1,854	n = 1,781	n = 1,781
NO2, per 10 ppb	1.19 (1.07–1.33)†	1.11 (0.96–1.28)‡	1.04 (0.74–1.44)
5 yr prior	n = 1,842	n = 1,769	n =1,769
NO2, per 10 ppb	1.19 (1.07–1.33)†	1.12 (0.97–1.29)‡	1.09 (0.77–1.53)

Definition of abbreviation: NO₂ = nitrogen dioxide.

NO₂ average exposure estimates (in 10 ppb units), over 1–5 years before sleep assessment, presented as odds ratios (95% confidence interval).

^*Adjusted for age, sex, body mass index, obstructive sleep apnea (apnea–hypopnea index ≥ 15) (model 1); plus race/ethnicity, income, smoking status, diabetes, hypertension, short sleep duration (< 6 h), and residential socioeconomic status (model 2); plus site (model 3).

^†P < 0.05.

^‡P < 0.10.