Six minute walk distance is a predictor of survival in patients with chronic obstructive pulmonary disease undergoing pulmonary rehabilitation.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a progressive and distressing disease with a trajectory that is often difficult to predict. OBJECTIVE: To determine whether initial 6 min walk distance (6MWD) or change in 6MWD following inpatient pulmonary rehabilitation (PR) predicted survival. METHODS: Patients referred for PR in 2010 were studied in a retrospective chart review. Measures of 6MWD before and following PR were recorded. Initial 6MWD was categorized as ≥250 m, 150 m to 249 m and ≤149 m. Government databases provided survival status up until December 2013 and survival analyses were performed. Initial 6MWD and a minimally important difference (MID) of ≥30 m were used for survival analysis. RESULTS: The cohort consisted of 237 patients (92 men, 145 women) with severe COPD. Mean (± SD) forced expiratory volume in 1 s (FEV1) was 0.75±0.36 L, with a mean FEV1/forced vital capacity (FVC) ratio of 0.57±0.16. Overall three-year survival was 58%. Mean survival for the study period as per predefined categories of 6MWD of ≥250 m, 150 m to 249 m and ≤149 m was 42.2, 37.0 and 27.8 months (P<0.001), respectively, with a three-year survival of 81%, 66% and 34% observed, respectively. Overall mean change in 6MWD was 62±57 m, and a minimal improvement of ≥30 m was observed in 72% of patients. In the lowest walking group, early mortality was significantly higher among those who did not achieve minimal improvement. Older age, male sex and shorter initial 6MWD were negative predictors of survival. CONCLUSION: In patients with severe COPD, initial 6MWD was predictive of survival. Overall survival at three years was only 58% and was especially poor (34%) in patients with low (<150 m) initial walk distance.

Examination of pulse oximetry tracings to detect obstructive sleep apnea in patients with advanced chronic obstructive pulmonary disease.

Nocturnal hypoxemia and obstructive sleep apnea (OSA) are common comorbidities in patients with chronic obstructive pulmonary disease (COPD). The authors sought to develop a strategy to interpret nocturnal pulse oximetry and assess its capacity for detection of OSA in patients with stage 3 to stage 4 COPD. A review of consecutive patients with COPD who were clinically prescribed oximetry and polysomnography was conducted. OSA was diagnosed if the polysomnographic apnea-hypopnea index was >15 events/h. Comprehensive criteria were developed for interpretation of pulse oximetry tracings through iterative validation and interscorer concordance of ≥80%. Criteria consisted of visually identified desaturation 'events' (sustained desaturation ≥4%, 1 h time scale), 'patterns' (≥3 similar desaturation/saturation cycles, 15 min time scale) and the automated oxygen desaturation index. The area under the curve (AUC), sensitivity, specificity and accuracy were calculated. Of 59 patients (27 male), 31 had OSA (53%). The mean forced expiratory volume in 1 s was 46% of predicted (range 21% to 74% of predicted) and 52% of patients were on long-term oxygen therapy. Among 59 patients, 35 were correctly identified as having OSA or not having OSA, corresponding to an accuracy of 59%, with a sensitivity and specificity of 59% and 60%, respectively. The AUC was 0.57 (95% CI 0.55 to 0.59). Using software-computed desaturation events (hypoxemia ≥4% for ≥10 s) indexed at ≥15 events/h of sleep as diagnostic criteria, sensitivity was 60%, specificity was 63% and the AUC was 0.64 (95%CI 0.62 to 0.66). No single criterion demonstrated important diagnostic utility. Pulse oximetry tracing interpretation had a modest diagnostic value in identifying OSA in patients with moderate to severe COPD.

Using a virtual game system to innovate pulmonary rehabilitation: safety, adherence and enjoyment in severe chronic obstructive pulmonary disease.

OBJECTIVE: The present pilot study tested the use of a virtual game system (VGS) for exercise training in patients with moderate to very severe chronic obstructive pulmonary disease undergoing pulmonary rehabilitation (PR). Safety, feasibility, enjoyment and adherence were assessed. METHODS: VGS (Wii [2006], Nintendo, USA) games were prescreened and categorized into lower- and upper-body workouts. Patients admitted for a three- to four-week inpatient PR program exercised daily. They were provided an opportunity to individually engage in VGS sessions three times weekly, varying with length of stay. Dyspnea, oxygen saturation and heart rate were measured before, during and after game sessions. Patients were considered to be adherent if they attended at least 50% of VGS sessions. Adverse events and enjoyment were evaluated. RESULTS: Thirty-two patients with a mean (± SD) age of 66±9 years and a mean forced expiratory volume in 1 s of 0.72±0.40 L participated. Among the 25 patients completing the program, adherence was 76%, with a mean attendance rate of 64±35%. Mean dyspnea score was 1.5±1.1 before and 3.2±1.2 after exercise. Mean oxygen saturation changed from 94±3% to 91±5% (P<0.001), while heart rate increased from 88±15 beats/min to 102±18 beats/min (P<0.001). One patient reported chest pain requiring nitroglycerin spray and five experienced transient desaturation below 85% with play. Patients enjoyed the program (visual analogue score 8±2.6/10) and most would highly recommend it to others. CONCLUSIONS: Moderate exercise using a VGS was safe, feasible and enjoyed as an adjunct to inpatient PR. This modality may encourage patients to maintain physical activity after PR.

Integrated interdisciplinary care for patients with chronic obstructive pulmonary disease reduces emergency department visits, admissions and costs: a quality assurance study.

BACKGROUND: Dedicated programs for the management of chronic obstructive pulmonary disease (COPD) can reduce hospitalizations and improve quality of life. OBJECTIVE: To investigate whether health care utilization could be reduced by a newly developed integrated, interdisciplinary initiative that included a COPD nurse navigator who educates patients and families, transitions patients through various points of care and integrates services. METHODS: The present quality assurance, pre-post study included patients followed by a COPD nurse navigator from January 25, 2010 to November 5, 2011. Information regarding emergency department visits and hospitalizations, including lengths of stay, were obtained from hospital databases. Diagnoses were classified as respiratory or nonrespiratory, and used primary and secondary hospitalization diagnoses to identify acute exacerbations of COPD (AECOPD). Paired sign tests were performed. RESULTS: The sample consisted of 202 patients. Following nurse navigator intervention, significantly more patients experienced a decrease in the number of respiratory-cause emergency department visits (P<0.05), number of respiratory hospitalizations (P<0.001), total hospital days for respiratory admissions (P<0.001), number of hospitalizations with AECOPD (P<0.001) and total hospital days for admissions with AECOPD (P<0.001). Financial modelling estimated annual savings in excess of $260,000. CONCLUSION: The present quality assurance study indicated that the implementation of an integrated interdisciplinary program for the care of patients with COPD can improve patient outcomes despite the tendency of COPD to worsen over time.

Unilateral hemidiaphragm weakness is associated with positional hypoxemia in REM sleep.

BACKGROUND: Patients with unilateral diaphragmatic paralysis (UDP) have been reported to have varied respiratory symptoms and often reduced lung function. We sought to describe the polysomnographic respiratory characteristics in patients with UDP without obstructive sleep apnea. METHODS: We prospectively collected 5 cases with clinical investigation regarding symptoms, lung function, and nocturnal polysomnography. The respiratory sleep characteristics were analyzed with standardized scoring of respiratory events in 30-sec epochs and comparison according to sleep-wake stages and body position with respect to oximetry. The cases were compared to 5 controls matched for age, gender, and body mass index. RESULTS: Three of 5 patients had significant awake lung restriction with a mean (range) forced vital capacity of 1.89 (1.48-2.24) liters, 72% (45% to 102%) predicted. All had REM sleep with few apneas and episodes of prolonged hypopneas characterized by important desaturation noted on oximetry. These desaturations were greatest during REM sleep when the patients slept supine with a mean (SD) saturation of 90.8% (4.5%) and minimum of 64% or on the side unaffected by UDP with a mean saturation of 87.8% (5.3%) and minimum of 67% (p < 0.0001 compared to same positions awake). Other sleep stages had few, if any significant desaturations and these events rarely occurred when the patient slept in the supine position. Saturation was lower in all sleep-wake stages and sleep positions compared to controls (p < 0.0001). CONCLUSION: Patients with UDP demonstrate position-dependent hypopneas in REM sleep with frequent desaturations.

Development of a patient needs assessment model for pulmonary rehabilitation.

Patients with chronic obstructive pulmonary disease are often referred to pulmonary rehabilitation programs to manage their symptoms and the consequences of the disease on their lives. Finding ways to target programs to a specific patient's needs could help improve individual response to the program. The purpose of this study was to develop a conceptual model for the assessment of patients' rehabilitation needs by using a grounded theory approach. Focus groups, consultations of medical charts, and a literature review helped us develop a conceptual model characterized by the following categories: need recognition, knowledge, motivation, expectations, goals, ability to fulfill needs, and the ability for personal adjustment. Based on a content matrix reflecting the conceptual model and disease consequences, items to be included in a prototype instrument were formulated and a preliminary validation phase was conducted.

Oxygen desaturation during a 6 min walk test is a sign of nocturnal hypoxemia.

UNLABELLED: BACKGROUND/ OBJECTIVES: Patients with chronic obstructive pulmonary disease (COPD) may experience sleep disordered breathing with nocturnal desaturation. An exploratory study was performed to determine whether any commonly measured clinical parameters were useful in predicting nocturnal desaturation in patients with COPD. A validation study was subsequently performed to confirm the utility of the parameter identified in the exploratory study as most useful in this regard. METHODS: A total of 103 (exploratory cohort) and 200 (validation cohort) consecutive patients with COPD admitted for pulmonary rehabilitation were evaluated. Standard outcome measures including nocturnal oximetry and the 6 min walk test (6MWT) on room air with continuous pulse oximetry were assessed. Patients with sleep apnea or those undergoing long-term oxygen therapy were excluded. RESULTS: In the exploratory study, the mean (± SD) patient age was 70 ± 9.9 years, with forced expiratory volume in 1 s of 0.76 ± 0.34 L, which was 36 ± 16% of predicted. Body mass index, arterial oxygen tension, oxygen saturation by pulse oximetry at rest and during the 6MWT all demonstrated significant correlations with percentage of time spent with a saturation <90%. When the lowest pulse oximetry during the 6MWT was ≤88%, 10 of 21 patients demonstrated a saturation <90% for at least 30% of sleep time. This measure yielded a positive likelihood ratio of 3.77 (95% CI 1.87 to 7.62) compared with those who did not reach this threshold value. The validation study confirmed similar detection characteristics. CONCLUSIONS: Results from the present study suggest that monitoring oxygen saturation changes during a 6MWT is useful in helping to identify COPD patients who may experience significant nocturnal desaturation.

Patient knowledge in chronic obstructive pulmonary disease: back to basics.

Patient education is integral to the care of patients with chronic obstructive pulmonary disease (COPD), and a cornerstone of self-management in chronic illness. We aimed to assess information needs and knowledge of patients with COPD. The Lung Information Needs Questionnaire (LINQ) and The Mount Sinai Hospital Questionnaire (MSHQ) were used. The LINQ identifies what COPD information the patient has, or is lacking. Higher scores in the LINQ define a greater information need. The MSHQ assesses a patients' COPD knowledge. Higher scores in the MSHQ questionnaire indicate greater knowledge. Subjects, in (n = 38) and outpatients (n = 43) were aged (mean ± SD) 69 ± 9 years, 53% were women, and 36% had not completed high school. COPD was diagnosed 9 ± 7 years previously. Forty percent had recalled receiving specific COPD education. Mean forced expiratory volume in 1 second (FEV1) was 1.1 ± 0.6 Liters. Patients on average had a 29 ± 14% need for information as assessed by the LINQ. Patients indicated a 52 ± 34% need for information on diet and 43 ± 25% for self-management. The mean total score for the MSHQ was 71 ± 13%. The score on treatment was 76 ± 20% and 60 ± 14% on pathophysiology. There was a positive relationship between having prior COPD education, finishing high school and total MSHQ score (p < 0.05) and a positive correlation of prior COPD education and reduced LINQ total score (p < 0.01). Patients with COPD have received information and demonstrate some knowledge about their disease. However, there remains a need for more education on diet and self-management.

Fatigue in COPD: prevalence and effect on outcomes in pulmonary rehabilitation.

Patients with chronic obstructive pulmonary disease (COPD) complain of dyspnea and fatigue. We sought to estimate the prevalence of high fatigue in this population and to determine whether individuals with high fatigue had a different response to pulmonary rehabilitation. This observational study was embedded within a randomized trial. Participants underwent 3 months of pulmonary rehabilitation including education and exercise training. We divided 251 individuals into low and high fatigue groups using population normal scores of the SF-36 vitality domain. Baseline data included spirometry, 6-minute walk distance (6MWD), peak exercise capacity, constant workrate cycling endurance time, and questionnaires including the St. George's and Chronic Respiratory questionnaires (SGRQ, CRQ). The response to pulmonary rehabilitation was evaluated using changes in these measures at 3 months and 1 year after entry. High fatigue was present in 97/251 (39%) of patients. High fatigue patients were younger, had more depressive symptoms, greater dyspnea and poorer SGRQ scores (p < 0.01). They also had lower 6MWD, endurance times, and peak volume of oxygen consumption (VO(2); p < 0.05). Patients in both groups improved similarly in their dyspnea, the 6MWD and endurance time. High-fatigue patients had greater improvements in both the CRQ fatigue (by 0.74 more points) and the SGRQ scores (by 6.0 points; p < 0.01), with clinically significant gains maintained at 1 year. This study suggests that high levels of fatigue is a common feature in patients with COPD. They have a lower exercise capacity and a lower health status. However, they benefit from pulmonary rehabilitation.

Leak profile inspection during nasal continuous positive airway pressure.

BACKGROUND: Patients treated with nasal continuous positive airway pressure (nasal CPAP) for obstructive sleep apnea (OSA) often have adverse effects from and poor adherence to CPAP. OBJECTIVE: To describe abnormal CPAP leak profiles and assess inter-observer reliability in identifying leak profiles and the correlation of leak profiles with leak rate and clinical outcomes. METHODS: In a sleep-disorders clinic we prospectively studied 35 consecutive patients newly diagnosed with moderate or severe OSA, and who had undergone polysomnographic diagnosis and nasal CPAP titration. We analyzed the data recorded by their CPAP machines during their first week of CPAP. Two independent clinical sleep specialists inspected each night's leak profiles. We defined a "continuous" leak profile segment as a leak increase of ≥ 20 L/min for > 5 min. We defined a "serrated" leak profile segment as a leak that oscillated up to ≥ 20 L/min in ≤ 5 min. With a validated questionnaire, we surveyed the patients about adverse effects. RESULTS: Overall inter-observer agreement was 88% for continuous leak and 92% for serrated leaks. The kappa values were 0.76 and 0.85, respectively. Deviance (± 2 SD) between scorers was -14% to 11% for continuous leaks, and -15% to 9% for serrated leaks. The duration of manually scored profiles correlated modestly but significantly with the machine-recorded leaks. The mean ± SD adherence to CPAP was lower in the patients with the highest quartile of continuous leak (5.28 ± 2.24 h/night versus 6.66 ± 1.72 h/night). Adverse effects increased with increasing serrated leak (P = .01). CONCLUSIONS: Manually scored leak profiles in patients treated with nasal CPAP can guide clinicians with respect to short-term adherence to nasal CPAP and adverse effects.

Success in pulmonary rehabilitation in patients with chronic obstructive pulmonary disease.

BACKGROUND: Pulmonary rehabilitation (PR) is beneficial for some, but not all, patients with chronic lung disease. OBJECTIVES: To determine the success rate of a comprehensive PR program for patients with chronic obstructive pulmonary disease (COPD) and to characterize the differences between responders and nonresponders. METHODS: A chart review was performed on patients with a clinical diagnosis of COPD who were referred for PR. Success was defined according to clinically important changes in St George's Respiratory Questionnaire scores and/or 6 min walk test distance. RESULTS: The majority of subjects were men (58%) with a mean (± SD) age of 69±10 years (n=177). Sixty-two per cent of participants had a successful outcome with PR, with proportionally more responders noting subjective improvement than objective improvement on a 6 min walk test (73% versus 51%). Subjects with poor baseline St George's Respiratory Questionnaire scores tended to improve the most (P=0.011 [ANOVA]). Successful participants had a greater forced expired volume in 1 s (1.1 L versus 0.9 L; P<0.05) and a lower BODE index (body mass index, airflow obstruction, dyspnea, and exercise capacity index) at baseline (9.6 versus 10.3; P<0.05). Success of PR was not correlated with age, sex, chronic hypoxemic respiratory failure or other chronic conditions. Successful participants were more likely to be compliant and to experience fewer adverse events (P≤0.001). CONCLUSIONS: Our study reinforced the belief that the majority of participants with COPD benefit from PR. Few baseline characteristics were predictive of success. Subjectively measured improvement occurred more frequently than objectively measured improvement and was greatest in those with the poorest baseline values.

Sleep disorder symptoms are common and unspoken in Canadian general practice.

OBJECTIVE: Primary care patients were surveyed for what sleep disorder symptoms they discussed with their physicians. Their responses were compared with those of new Sleep clinic patients. The goal was to discover what symptom presentation leads to a successful referral to a sleep clinic. METHODS: We recruited two samples: 191 older Primary care patients and 138 Sleep clinic patients. Participants completed the Sleep Symptom Checklist (SSC). This consists of 21 symptoms in four domains: insomnia, sleep disorder, daytime symptoms and psychological distress. All respondents indicated which symptoms had been discussed with their physician in the past year. Primary care subjects were designated as Decliners (completed SSC, refused further evaluation), Dropouts [completed some evaluation steps, but not polysomnography (PSG)] and Completers (completed PSG). RESULTS: Primary care participants frequently had symptoms but relatively few had discussed them with their doctor. Sleep clinic participants discussed significantly more symptoms with their referring physician than did Primary care Dropouts or Decliners in all categories except psychological distress. Primary care Completers, 88.5% of whom were ultimately diagnosed with sleep apnoea/hypopnoea syndrome and/or periodic limb movement disorder, also discussed their sleep disorder symptoms less frequently than did Sleep clinic patients but tended to give more prominence to symptoms of insomnia and impaired daytime function. CONCLUSIONS: The findings suggest that Primary care patients often have symptoms they do not discuss, even when a primary sleep disorder exists. The brief SSC checklist, developed in our laboratory, has potential to improve the referral rates of older primary care patients who have sleep disorder.

Evidence of interrelated side effects with reduced compliance in patients treated with nasal continuous positive airway pressure.

OBJECTIVES: Patients treated for obstructive sleep apnea syndrome (OSAS) with nasal continuous positive airway pressure (nCPAP) often have side effects and poor compliance. Our objectives were to explore their side effects when treated with nCPAP and to validate the association of a side effect syndrome with the outcomes of sleep quality, daytime sleepiness and nCPAP compliance. METHODS: Prospective exploratory and subsequent validation study using questionnaires was performed in a tertiary-care sleep-disorders clinic. Consecutive patients with polysomnographic diagnosis and nCPAP titrations treated at least 3 months with single-pressure nCPAP were studied. In the first survey, 114 patients were questioned of whom 89 (78%) qualified for exploratory analysis. In the validation survey of 122 patients, 104 (85%) were studied. Subjects were interviewed and their nCPAP meters were queried. RESULTS: In the first survey, 3 side effects were often found together and each found to be correlated to compliance: mouth leak with nCPAP, nasal congestion, and taking off the mask prematurely. In the validation study, 34% of participants met a syndrome definition with at least 2 of 3 major side effects. Mean (SD) compliance was lower in patients with the syndrome: 4.97 (1.98) vs. 6.42 (1.56) hours per night (p=0.0001). Poor sleep quality and lower satisfaction with nCPAP were associated with the syndrome. CONCLUSIONS: The syndrome of mouth leak, taking off the nCPAP mask prematurely and nasal congestion is frequent in patients treated with nCPAP. This is associated with lower compliance and poor sleep quality.

Long-term compliance with continuous positive airway pressure in patients with obstructive sleep apnea.

BACKGROUND: Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnea (OSA). However, compliance is a significant problem and has been incompletely assessed in long-term studies. OBJECTIVE: To assess the long-term compliance of OSA patients with CPAP therapy. SUBJECTS: Eighty patients who had had a diagnosis of OSA at least four years previously and received a written prescription for CPAP were evaluated. METHODS: Subjects were identified by reviewing sleep laboratory records. Participants were contacted by telephone and were asked to quantitate their CPAP use (hours per night, nights per week) and to evaluate whether there had been improvement in symptoms. Those who commenced but subsequently abandoned therapy and those who never initiated treatment were questioned about their reasons for noncompliance. RESULTS: Patient demographics included mean (+/- SD) age (58+/-11 years), male sex (70 of 80 patients [88%]) and mean apnea-hypopnea index (70+/-44 events/h). At the time of the interview (64.0+/-3.7 months after diagnosis), 43 of 80 patients (54%) were still using CPAP and most reported an improvement in symptoms. Twelve of 80 patients (15%) had abandoned CPAP after using it for 10.1+/-15.5 months, and 25 of 80 patients (31%) had never commenced therapy after initial diagnosis and CPAP titration. Analysis of scores reflecting initial patient sleepiness revealed a significant association of this symptom with subsequent CPAP compliance. CONCLUSION: Although many patients with OSA derive subjective benefit from, and adhere to treatment with CPAP, a significant proportion of those so diagnosed either do not initiate or eventually abandon therapy. Initial experience with CPAP appears to be important, reinforcing the need for early education and support in these patients.

Sleep and aging: 2. Management of sleep disorders in older people.

The treatment of sleep-related illness in older patients must be undertaken with an appreciation of the physiologic changes associated with aging. Insomnia is common among older people. When it occurs secondary to another medical condition, treatment of the underlying disorder is imperative. Benzodiazepines, although potentially effective, must be used with care and in conservative doses. Daytime sedation, a common side effect, may limit use of benzodiazepines. Newer non-benzodiazepine drugs appear to be promising. Rapid eye movement (REM) sleep behaviour disorder can be treated with clonazepam, levodopa-carbidopa or newer dopaminergic agents such as pramipexole. Sleep hygiene is important to patients with narcolepsy. Excessive daytime sleepiness can be treated with central stimulants; cataplexy may be improved with an antidepressant. Restless legs syndrome and periodic leg-movement disorder are treated with benzodiazepines or dopaminergic agents such as levodopa-carbidopa and, more recently, newer dopamine agonists. Treatment of obstructive sleep apnea includes weight reduction and proper sleep positioning (on one's side), but may frequently necessitate the use of a continuous positive air-pressure (CPAP) device. When used regularly, CPAP machines are very effective in reducing daytime fatigue and the sequelae of untreated obstructive sleep apnea.

Sleep and aging: 1. Sleep disorders commonly found in older people.

Aging is associated with several well-described changes in patterns of sleep. Typically, there is a phase advance in the normal circadian sleep cycle: older people tend to go to sleep earlier in the evening but also to wake earlier. They may also wake more frequently during the night and experience fragmented sleep. The prevalence of many sleep disorders increases with age. Insomnia, whether primary or secondary to coexistant illness or medication use, is very common among elderly people. Rapid eye movement (REM) sleep behaviour disorder and narcolepsy, although less common, are frequently not considered for this population. Periodic leg-movement disorder, a frequent cause of interrupted sleep, can be easily diagnosed with electromyography during nocturnal polysomnography. Restless legs syndrome, however, is diagnosed clinically. Snoring is a common sleep-related respiratory disorder; so is obstructive sleep apnea, which is increasingly seen among older people and is significantly associated with cardio-and cerebrovascular disease as well as cognitive impairment.

Prevalence of persistent sleep apnea in patients treated with continuous positive airway pressure.

STUDY OBJECTIVE: There are limited data on the prevalence of persistent obstructive sleep apnea (OSA) in patients who are clinically asymptomatic with continuous positive airway pressure (CPAP). Our objectives were to estimate the prevalence of persistent OSA and to explore the parameters that may be capable of discriminating these patients. DESIGN: Prospective survey. SETTING: A tertiary-care sleep-disorders clinic. PARTICIPANTS: Consecutive patients treated with single-pressure CPAP for at least 3 months were studied. All had undergone CPAP titrations and were compliant with treatment. They denied snoring or persistent excessive daytime somnolence. Of 114 who qualified, 101 were studied. INTERVENTIONS: Subjects underwent 16-channel polysomnography with electroencephalogram and pneumotachometer while using their CPAP. MEASUREMENTS AND RESULTS: Seventeen of 101 subjects (17%) had an apnea-hypopnea index of over 10. Fifty-one had only split-night protocols for CPAP titration. There was no significant difference between participants with persistent OSA and those with an apnea-hypopnea index < 5 with regard to age, sex, time since diagnosis, reported snoring, change in weight, or quality of life (all p > .10). Mean current CPAP level was higher, with a mean +/- SD 10.6 +/- 2.8 versus 8.6 +/- 2.3 cm H2O (p = .002). Unresolved air leak related to CPAP was more frequent in the patients with persistent OSA. Morning headaches, nonrestorative sleep, and frequent central apneas on the CPAP titration were all associated with persistent OSA. CONCLUSIONS: Persistent OSA is frequent in patients treated with CPAP. This is more frequent in patients with high body mass index, higher prescribed pressures, and unresolved mask leak.

Clinical reproducibility of the Epworth Sleepiness Scale.

STUDY OBJECTIVES: The Epworth Sleepiness Scale (ESS) is widely used as a subjective measure of sleepiness. To our knowledge, no study has evaluated its reproducibility in the clinical setting. METHODS: A retrospective chart review of patients referred to the sleep clinic at Mount Sinai Hospital for evaluation of sleep-disordered breathing from a local private snoring clinic between January 2000 and October 2001 was carried out. Patients were snorers and referred because of suspicion of sleep apnea. Clinical information including results of the ESS scores from the two institutions was analyzed to evaluate reproducibility. RESULTS: There were 142 patients evaluated: 76% men with a mean (SD) age of 44 (11) years, body mass index of 31 (6.1) kg/m(2), and apnea-hypopnea index of 41 (34) events per hour. The average time interval between ESS administrations was 71 (92) days. The average ESS score was 11.1 (5.2) at the Snoring Clinic and 11.2 (5.3) at Mount Sinai Hospital. The Bland-Altman plot of the difference against the mean of the ESS score demonstrated a wide scatter of data and variability where 2 SDs ranged 7.8 above and below the mean. A difference between the sequential ESS scores of 5 or more was seen in 23% of the subjects. CONCLUSION: The ESS score is highly variable when administered sequentially to a clinical population being evaluated for a potential sleep-related breathing disorder.