Agreement between stroke patients and family members for ascertaining pre-stroke risk for sleep apnea

Ascertaining self-reported information about the risk for pre-stroke obstructive sleep apnea (OSA) in the acute stroke period is challenging as many stroke patients have deficits that hinder communication. We examined agreement between stroke patients without communication limitations and family members (proxy) in the pre-stroke risk for OSA.

Patient-proxy pairs (n=42) were interviewed independently as part of the Brain Attack Surveillance in Corpus Christi (BASIC) Project from May 2010 to April 2011. The Berlin questionnaire was used to measure a high risk for OSA defined as the presence of at least two of the following conditions: (1) snoring behaviors/witnessed apneas, (2) daytime sleepiness, and (3) hypertension or obesity. Patient-proxy agreement was assessed using a κ coefficient.

Forty-three percent of patients self-identified as being at high risk for sleep apnea, and 45% of proxies identified patients as high risk. Patient-proxy agreement for high risk for pre-stroke OSA was fair (κ=0.28) with better agreement for spouses and children proxies (κ=0.38) than for other family members. Agreement also was fair for most individual questions.

Spouse and child proxy use of the Berlin questionnaire may be an option to assess a patient's pre-stroke likelihood of sleep apnea. Whereas prospective studies of incident stroke in patients with and without objectively confirmed sleep apnea would require formidable resources, our results suggest that an alternative strategy may involve proxy use of the Berlin questionnaire in a retrospective study design.