Being mindful of later-life sleep quality and its potential role in prevention.

Abstract

Older adults commonly report disturbed sleep, and an expanding literature suggests that poor sleep increases the risk of adverse health outcomes.1 In this issue of JAMA Internal Medicine, Black et al2 present a randomized clinical trial (RCT) among adults 55 years and older with moderately disturbed sleep, comparing a sleep hygiene intervention with a community-based mindfulness meditation intervention. They assess the outcomes of global sleepquality, insomnia symptoms, fatigue, and depressive symptoms. As the authorsexplain, effectivenonpharmacological interventions that are both “scalable” and “community accessible” are needed to improve disturbed sleep and prevent clinical levels of insomnia. This is imperative given links between insomnia and poor health outcomes, risks of sleepmedication use, and the limited availability of health care professionals trained in effectivenondrug treatments suchasbehavior therapyandcognitivebehavioral therapy for insomnia.This contextmakes the positive results of this RCT compelling. Behavior therapy and cognitive behavioral therapy for insomnia arenonpharmacological interventions for clinical levels of insomnia, with known efficacy across age groups, including inolder adults.However, awarenessof these therapies is lowamongphysicians and the general public, and the availability of trainedhealth careprofessionals to administer these treatments is below what is required to address the clinical need.Fortunately, initiatives tomorewidelydisseminate these interventions have begun. The Department of Veterans Affairs has been training non–sleep specialist physicians, psychologists, nurses, and socialworkers to deliver cognitive behavioral therapy for insomniawithin its primary care,mental health, and other clinics.3 Outside of the Department of Veterans Affairs, a nurse-administered brief behavioral treatment for insomniahasbeendevelopedforuse inprimarycare.4 Althoughthesearepositivedevelopments, suchtreatmentsare notyetwidely available inprimary care settings, rendering the outside-of-the-clinic approachofBlacket al2 to treatment (and perhaps prevention) of disturbed sleep all themore relevant. There are some important methodological aspects of the study by Black et al2 thatwarrant discussion. The authors did not require participants in their RCT tomeet criteria for a particular common sleep disorder such as insomnia, sleepdisorderedbreathing, or restless legs syndrome. Instead, they excluded individuals reporting sleep-disordered breathing or restless legs syndrome and recruited individuals with a selfreported Pittsburgh Sleep Quality Index (PSQI) exceeding 5, whichsuggestspoor sleepquality.5 Sleepquality is abroadconstruct that has been defined in various ways. It encompasses and is affectedbyseveral aspectsof sleep, including sleep fragmentation, extended latency to sleep onset, perceived restfulness of sleep, and (according to some definitions) sleep duration.5 The cutoff value of greater than 5 on the PSQI was originally selected for its ability to differentiate poor sleepers (definedas individualswithproblems fallingor stayingasleep, excessivedaytime sleepiness, or depression) fromgood sleepers with no sleep complaints.5 Some may question the decision to recruit study participants on the basis of a PSQI score rather than, for example, an insomniadiagnosis.However, the selection of the PSQI makes sense given the epidemiological evidence that among older adults a PSQI exceeding 5 is associated with adverse health outcomes, including frailty and lowercognitive function.6,7Therefore, thePSQIcutoffofgreater than 5 should identify individuals at risk for poor sleeprelated health outcomes and would likely capture a greater number of them than would be identified by more stringent diagnostic criteria for insomnia. These are important qualities for a community-based intervention inwhich prevention of clinical insomnia and its outcomes may eventually be the goal. In line with this, while Black et al2 describe their study participants as having moderate sleep problems, a PSQI exceeding5 canalso reflect severedisturbances. Therefore, their sample likely included older adults with subclinical insomnia and others with clinical levels of insomnia. In addition, there may well have been cases of sleep-disordered breathingand restless legs syndrome in the samplegiven that thehistory of these disturbances was screened for only via selfreport. The likelihood that their sample contained individuals with sleep disturbances other than insomnia and that their sleepmay have beenmore thanmoderately disturbedmakes the authors’ positive findings all the more impressive. This excellent study raises somequestions that need tobe answered in future research.Forexample,whichaspectsof the broad construct of sleep quality does the mindfulness meditation intervention improve?While the global PSQI scorewas the primary outcome of this trial, how does the intervention affect the different PSQI components,5 including sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, sleepmedications, anddaytimedysfunction? Inaddition, the mechanisms by which mindfulness meditation affects sleep remain unclear. Indeed, depression and fatigue were classifiedbyBlack et al2 as secondary “sleep-relateddaytime impairment” outcomes andwere improvedby themindfulness intervention. However, rather than being consequences of improvements in insomnia, it is possible that improvements in depression and fatigue mediated the effect of mindfulness on sleep quality. Future studies with repeatedassessmentof theseputativemediators throughout the intervention would help determine whether this is the case. Finally, theauthors indicated that theirRCTwas the first study Related article page 494 Research Original Investigation Mindfulness Meditation in Sleep-Disturbed Adults