Table 5.

INAP Items and Sub-scales

Item or Sub-scale	Format & Number of Items Included	Source
Self-efficacy Measure in Sleep Apnea (SEMSA) – Outcome Expectancies sub-scale	4-point Likert scale; 9 items	Available with permission from author*
Social Cognitive Theory Questionnaire in Sleep Apnea – Self-efficacy sub-scale	5-point Likert scale; 5 items	Publicly available†
Health Literacy Questionnaire How often do you have problems learning about your medical condition because of difficulty understanding written information?	5-point Likert scale; 1 item	Publicly available‡
BMI	1 item	-
Marital Status Married Not married	1 item	-
Presenting symptoms for seeking care at sleep center Restless sleep Snoring Breathing stops in sleep Sleepiness during day Other	1 item	-
Gender Male Female	1 item	-

^*Weaver TE, Maislin G, Dinges DF, et al. Self-efficacy in sleep apnea: Instrument development and patient perceptions of obstructive sleep apnea risk, treatment benefit, and volition to use continuous positive airway pressure. Sleep 2003;26:727-32.

^†Stepnowsky CJ, Marler MR, Ancoli-Israel S. Determinants of nasal CPAP compliance. Sleep Medicine 2002;3: 239-47.

^‡Chew LD, Bradley KA, Boyko EJ. Brief questions to identify patients with inadequate health literacy. Family Medicine 2004;36: 588-94.