Table 3.

Clinical studies evaluating QOS and/or daytime functioning and/or QOL in patients with comorbid insomnia

Study reference	Patient population	Baseline insomnia diagnosis/assessment	Assessment scales used	QOS and QOL baseline measures and other outcomes
28	Chronic heart failure (n = 223)	No formal baseline assessment of insomnia	USI-CHF, ESS, MOS SF-36, MLWHF Questionnaire	HR-QOL, measured by SF-36, was reduced in patients with heart failure versus the general population aged ≥ 75 years, for all dimensions except bodily pain (P < 0.05). Heart failure patients with difficulty initiating and maintaining sleep and early-morning awakenings had the worst HR-QOL, particularly for general health, vitality, and social functioning
30	Recovering alcoholics (n = 60)	DSM-IV, sleep-onset latency >30 min for ≥3 nights/week	PSQI global score	Sleep quality ranged from 12.4 to 13.3
36	Patients on hemodialysis (n = 89)	No formal baseline assessment of insomnia	MOS-SF-36, PSQI	‘Poor sleepers’ had a reduced QOL across all domains, and mental and physical component scores were inversely correlated with sleep quality (P < 0.01) 71% of this patient cohort were ‘poor sleepers’ (global PSQI > 5)
63	Cancer patients (n = 954)	EORTC-QLQ-C30 insomnia subscale	Ferrans and powers QLI	Insomnia was strongly related to the health and physical functioning aspects of QOL. A 30-point increase in QLQ-C30 was associated with a 2.01-point reduction in health and physical functioning and a 1.3-point reduction in psychological and spiritual functioning
37	Renal transplantation (n = 1067)	AIS	KDQOL-SF (including MOS SF-36)	The presence of restless legs syndrome was associated with a threefold increase in insomnia (P = 0.001), and was independently associated with impaired HR-QOL. Physical and mental aspects of QOL were significantly reduced in patients with restless legs syndrome versus those without (P ≤ 0.01)
44	Inactive inflammatory bowel disease (n = 119)	Patients with sleep disorders were excluded	IBD QOL Questionnaire PSQI	QOL was inversely correlated with sleep quality. Analysis of the psychosocial component score revealed more anxiety in patients with IBD versus controls IBD patients had prolonged sleep latency, frequent sleep fragmentation, reduced daytime energy, higher usage of sleeping medications, and poor overall sleep quality versus patients with inflammatory bowel syndrome and healthy controls

Abbreviations: QOS, quality of sleep; QOL, quality of life; USI-CHF, Uppsala Sleep Inventory-Chronic Heart Failure; ESS, Epworth Sleepiness Scale; MOS SF-36, Medical Outcomes Study 36-item Short-Form; MLWHF, Minnesota Living with Heart Failure; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; PSQI, Pittsburgh Sleep Quality Index; EORTC-QLQ, European Organization for Research Treatment of Cancer-Quality of Life Questionnaire; QLI, Quality of Life Index; AIS, Athens Insomnia Scale; KDQOL-SF, Kidney Disease QOL-SF.