Table 4.

Change in annual rate of COPD exacerbation resulting in hospitalization per 1-point increase in PSQI and co-variates in SPIROMICS, full models

	Model A: complete cases (n = 915)	p	Model B: complete cases, controlling for exacerbation history (n = 915)	p	Model C: imputed model (n = 1647)		Model D: imputed model, controlling for exacerbation history (n = 1647)
Pittsburgh Sleep Quality Index (PSQI)	1.08 (1.01–1.16)	.03	1.07 (1.00–1.15)	.05	1.07 (1.02–1.13)	.01	1.06 (1.01–1.12)	.02
Inter-visit change in PSQI	1.03 (0.96–1.11)	.34	1.02 (0.95–1.09)	.65	1.04 (0.98–1.11)	.14	1.03 (0.97–1.09)	0.34
Age	0.94 (0.75–1.17)	.57	1.02 (0.82–1.27)	.89	0.91 (0.77–1.08)	.29	0.95 (0.81–1.12)	.55
Sex	1.05 (0.69–1.61)	.81	1.04 (0.69–1.58)	.84	1.12 (0.82–1.53)	.49	1.06 (0.78–1.44)	.73
BMI	0.79 (0.62–1.01)	.06	0.80 (0.63–1.01)	.06	0.84 (0.71–1.00)	.055	0.84 (0.70–1.00)	.05
Race
Non-Hispanic White	Referent		Referent		Referent		Referent
Black	3.49 (1.81–6.73)	<.001	3.55 (1.84–6.85)	<.001	2.13 (1.37–3.31)	.001	2.29 (1.47–3.56)	<.001
Other	0.60 (0.21–1.74)	.35	0.65 (0.23–1.82)	.42	0.66 (0.33–1.31)	.24	0.69 (0.35–1.35)	.28
Asthma
No	Referent		Referent		Referent		Referent
Uncertain	0.26 (0.08–0.89)	.03	0.28 (0.09–0.87)	.03	0.44 (0.20–0.96)	.04	0.44 (0.20–0.95)	.04
Yes	1.07 (0.65–1.76)	.79	1.02 (0.63–1.66)	.93	1.51 (1.07–2.15)	.02	1.36 (0.96–1.93)	.08
Hospital Depression Scale score	0.98 (0.90–1.07)	.71	1.00 (0.92–1.08)	.92	1.01 (0.96–1.07)	.63	1.03 (0.97–1.09)	0.32
Hospital Anxiety Scale score	1.03 (0.96–1.11)	.41	1.02 (0.95–1.09)	.61	0.99 (0.94–1.05)	.76	0.98 (0.93–1.03)	0.41
Smoking pack-years	1.25 (0.97–1.62)	.08	1.26 (0.98–1.60)	.07	1.18(0.99–1.42)	.07	1.19(1.00–1.42)	.05
Percentage predicted post- bronchodilator FEV1	0.62 (0.47–0.82)	.001	0.64 (0.48–0.84)	.002	0.57 (0.46–0.70)	<.001	0.59 (0.48–0.73)	<.001
COPD Assessment Test score	1.03 (0.99–1.07)	.15	1.02 (0.99–1.06)	.21	1.02 (0.99–1.05)	.15	1.02 (0.99–1.05)	.17
LAMA usage	1.19 (0.77–1.84)	.43	0.96 (0.62–1.49)	.87	1.13 (0.81–1.55)	.47	1.03 (0.75–1.42)	.86
LABA-ICS usage	2.79 (1.79–4.43)	<.001	2.43 (1.57–3.77)	<.001	1.50 (1.07–2.10)	.02	1.39 (1.00–1.94)	.049
Comorbidity count	1.40 (1.12–1.76)	.003	1.39 (1.11–1.)	.004	1.22 (1.01–1.47)	.04	1.23 (1.02–1.48)	.03
Exacerbations in year prior to enrollment	NA		1.64 (1.31–2.05)	<.001	NA		1.43 (1.24–1.66)	<.001
Area Deprivation Index (ADI)	0.90 (0.72–1.14)	.39	1.00 (0.93–1.08)	.93	0.98 (0.83–1.16)	.85	1.02 (0.86–1.20)
Adversity–Opportunity Index	0.98 (0.87–1.09)	.70	0.99 (0.88–1.10)	.82	0.94 (0.86–1.03)	.15	0.96 (0.88–1.04)	.34

This model suggests that for every 1-point increase in baseline Pittsburgh Sleep Quality Index (PSQI) score, holding all other values equal, the risk of prospective COPD exacerbation is increased by 7% in the follow-up year. Or for every additional standard deviation change in post-bronchodilator FEV₁ at baseline, the risk of exacerbation is decreased by 38% in the follow-up year.

Bolded values statistically significant at α < 0.05. All results are presented as “point estimate (95% CI)”. Co-variates are presented as per 1-point change for scaled instruments, and per 1 standard deviation change for continuous variables.