PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a chronic restrictive lung disease associated with significant morbidity and mortality. Patients with IPF have frequent complaints of difficulty sleeping. Our goal is to assess measures of sleepiness and insomnia symptoms in IPF individuals compared to controls.
METHODS: We distributed questionnaires on sleepiness, the Epworth Sleepiness Scale (ESS), and a recently developed insomnia instrument, the SleepMed Insominia Index (SII), at an IPF support group meeting to individuals with IPF and their attending supporters. 49 subjects completed the questionnaire. We calculated mean ESS and SII scores using Student t tests for comparison of continuous variables. We used linear regression models adjusting for age and gender to determine differences in ESS and SII scores in IPF attendees versus their supporting counterparts without IPF (non-IPF group). We then plotted a matrix of disease severity based on level of sleepiness and insomnia symptoms.
RESULTS: Our study group consisted of 28 individuals with IPF (39.3% females) and 21 controls (76.2% females). The mean age (SD) was 68.7 (7.2) for the IPF group and 63.8 (8.4) for the non-IPF group (p=0.04). The mean ESS scores were 9.4 (4.9) for the IPF group and 7.2 (3.6) for the non-IPF group (p=0.08). Mean SII scores were 15.7 (7.9) for the IPF group and 8.5 (7.0) for the non-IPF group (p<0.01). When controlling for age and gender, SII values were still greater in the IPF group compared to controls (p<0.01).
CONCLUSION: This study demonstrates that there is no difference in degree of sleepiness between IPF and control groups. However, IPF individuals have more significant insomnia symptoms than counterparts, even when controlling for age and gender.
CLINICAL IMPLICATIONS: The matrix of ESS and SII has been studied in controls and patients with insomnia. This is the first study assessing the utility of the SII and ESS-SII matrix for screening in a chronic lung disease population.
DISCLOSURE: Richard Ko, No Financial Disclosure Information; No Product/Research Disclosure Information