Baseline Indicators Influencing Continuous Positive Airway Pressure Usage

Identification of claustrophobia prior to initiating CPAP using a 15-item Fear and Avoidance Scale predicted lower CPAP adherence at three months (95). Remedial measures to address such identified claustrophobia, logically, may improve adherence in those subjects. A patient's reporting "initial problems" after the first night of CPAP (using auto-titration) was the most powerful predictor of lower hours of CPAP "on time" at one-month follow-up (88). "Recent life events" and "living alone" were less robust predictors of adherence. In the same study, pretreatment measures of anxiety or depression failed to predict one-month adherence. Contrariwise, in another study low CPAP adherence predicted high anxiety scores, and low CPAP adherence and excessive daytime sleepiness predicted high depression scores in a questionnaire-based study of OSA patients (96). Predominant nose breathing rather than mouth breathing at outset predicted better adherence with CPAP at one year follow-up in moderate-severe OSA (97).

Progressing from diagnosis to titration to purchase of CPAP requires manifold interlocking promoting elements. Such progression, in many healthcare delivery systems requiring co-payment for CPAP, is facilitated by higher socioeconomic status, is correlated with higher measures of subjective sleepiness and severity of OSA (e.g., as quantified by RDI or AHI), and is abetted by support from the bed partner, referring physician and sleep lab staff (21).

Several other studies have confirmed that the pretreatment severity of sleepiness is correlated with the likelihood of greater usage of CPAP—that is, that patients with good objective usage or reported adherence are sleepier at baseline (53,86,92,98,99). Although daytime sleepiness as measured by the multiple sleep latency test (MSLT) improves following CPAP (87), baseline MSLT scores do not appear to predict CPAP adherence and it is controversial whether the amount of improvement in MSLT scores will predict adherence (86,98). It is possible that the maintenance of wakefulness test may be a better predictor of CPAP usage in patients with sleep apnea, but this is untested. Sleep fragmentation measured by an electroencephalographic neural network analysis or movement events on video recordings are reasonably correlated with CPAP adherence (100). Improved adherence has also been linked to the degree of improvement in sleep efficiency and quality between diagnostic and treatment studies (101). Other factors that may be related to reduced usage include previous palatal surgery and fewer years of education. Surprisingly, as mentioned above, considering the potential discomfort and potential mask leak, having a higher CPAP pressure level has not been shown to have a negative influence on adherence (12,17,18,53). In fact, it may be associated with improved adherence, though these data could be confounded by more marked symptoms (and thus a greater potential for symptom improvement) in patients requiring higher pressures (92).

Sleep Apnea

Sleep Apnea

Have You Been Told Over And Over Again That You Snore A Lot, But You Choose To Ignore It? Have you been experiencing lack of sleep at night and find yourself waking up in the wee hours of the morning to find yourself gasping for air?

Get My Free Ebook

Post a comment