Sharon Hurley

Noninferiority of functional outcome in ambulatory management of obstructive sleep apnea.

RATIONALE Home portable monitor testing is increasingly being used to diagnose patients with obstructive sleep apnea (OSA) and to initiate them on continuous positive airway pressure (CPAP) treatment. OBJECTIVES To compare functional outcome and treatment adherence in patients who receive ambulatory versus in-laboratory testing for OSA. METHODS Veterans with suspected OSA were randomized to either home testing or standard in-laboratory testing. Home testing consisted of a type 3 portable monitor recording followed by at least three nights using an automatically adjusting positive airway pressure apparatus. Participants diagnosed with OSA were treated with CPAP for 3 months. MEASUREMENTS AND MAIN RESULTS We measured the change in Functional Outcomes of Sleep Questionnaire score, with an a priori noninferiority delta of -1, and the mean daily hours of objectively measured CPAP adherence, with an a priori noninferiority delta of -0.75 hour/day. Of the 296 subjects enrolled, 260 (88%) were diagnosed with OSA, and 213 (75%) were initiated on CPAP. Mean ± SD functional outcome score improved 1.74 ± 2.81 in the home group (P < 0.001) and 1.85 ± 2.46 in the in-laboratory group (P < 0.0001). The lower bound of the one-sided 95% noninferiority confidence interval was -0.54. Mean ± SD hours of daily CPAP adherence were 3.5 ± 2.5 hours/day in the home group and 2.9 ± 2.3 hours/day in the in-laboratory group (P = 0.08). The lower bound of the one-sided 95% noninferiority confidence interval was 0.03. CONCLUSIONS Functional outcome and treatment adherence in patients evaluated according to a home testing algorithm is not clinically inferior to that in patients receiving standard in-laboratory polysomnography.

Validation of venous leg ulcer guidelines in the United States and United Kingdom

BACKGROUND Venous leg ulcers account for 85% of all lower-extremity ulcers, with treatment costs of 3 billion dollars and loss of 2 million workdays per year. The purpose of this study was to validate the clinical efficacy and cost effectiveness of multidisciplinary guidelines for the diagnosis and treatment of venous leg ulcers. METHODS Eighty (40 retrospective, 40 prospective) patients from the United States and United Kingdom were enrolled. RESULTS United States patients were 6.5 times and United Kingdom 2 times more likely to heal if a guideline was followed (P <0.001). A significant decrease was noted in healing time for both the United States and United Kingdom (P <0.01), and the median cost decreased significantly when the guideline was followed (P <0.01). CONCLUSIONS Implementation of a guideline for diagnosis and treatment of venous leg ulcers resulted in improvement in diagnosis, decrease in healing time, and an increase in healing rates resulting in lower costs.

Obstructive sleep apnea in patients undergoing bariatric surgery--a tertiary center experience.

BackgroundThe patient population that is evaluated for bariatric surgery is characterized by a very high body mass index (BMI). Since obesity is the most important risk factor for obstructive sleep apnea (OSA), sleep disordered breathing is highly prevalent in this population. If undiagnosed before bariatric surgery, untreated OSA can lead to perioperative and postoperative complications. Debate exists whether all patients that are considered for bariatric surgery should undergo polysomnography (PSG) evaluation and screening for OSA as opposed to only those patients with clinical history or examination concerning sleep disordered breathing. We examined the prevalence and severity of OSA in all patients that were considered for bariatric surgery. We hypothesized that, by utilizing preoperative questionnaires (regarding sleepiness and OSA respiratory symptoms) in combination with menopausal status and BMI data, we would be able to predict which subjects did not have sleep apnea without the use of polysomnography. In addition, we hypothesized that we would be able to predict which subjects had severe OSA (apnea–hypopnea index (AHI) > 30).MethodsThree hundred forty-two consecutive subjects, evaluated for bariatric surgery from November 1, 2005 to January 31, 2007 underwent overnight polysomnography and completed questionnaires regarding sleepiness, menopausal status, and respiratory symptoms related to OSA. Apneas and hypopneas were classified as follows: mild apnea 5 ≤ AHI ≤ 15, moderate apnea 15 < AHI ≤ 30, and severe apnea AHI > 30.ResultsThe overall sample prevalence of OSA was 77.2%. Of these, 30.7% had mild OSA; 19.3% had moderate OSA, and 27.2% had severe OSA. Among men, the prevalence of OSA was 93.6% and 73.5% among women. The mean AHI (events per hour) for men with OSA was 49.2 ± 35.5 and 26.3 ± 28.3 for women with OSA. Separate logistic regression models were developed for the following three outcomes: AHI ≥ 5 events per hour, AHI > 15 events per hour, and AHI > 30 events per hour. When predicting these three levels of OSA severity, the area under the curve (AUC) values were: 0.8, 0.72, and 0.8, respectively. The negative predictive value for the presence of sleep apnea (AHI ≥ 5) was 75% when using the most stringent possible cutoff for the prediction model.ConclusionsThe prevalence of OSA in all patients considered for bariatric surgery was greater than 77%, irrespective of OSA symptoms, gender, menopausal status, age, or BMI. The prediction model that we developed for the presence of OSA (AHI ≥ 5 events per hour) has excellent discriminative ability (evidenced by an AUC value of 0.8). However, the negative prediction values for the presence of OSA were too low to be clinically useful due to the high prevalence of OSA in this high-risk group. We demonstrated that, by utilizing even the most stringent possible cutoff values for the prediction model, OSA cannot be predicted with enough certainty. Therefore, we advocate routine PSG testing for all patients that are considered for bariatric surgery.

Predictors of continuous positive airway pressure use during the first week of treatment

This study aimed to identify pre‐treatment and immediate early treatment factors predicting continuous positive airway pressure (CPAP) use during the first week of therapy, when the pattern of non‐adherence is established. Four domains of potential predictors were examined: pre‐treatment demographic and clinical factors, patients’ perceived self‐efficacy, treatment delivery (mask leak and bothering side effects) and immediate disease reduction (residual respiratory events and flow limitation). The Autoset™ Clinical System objectively documented daily CPAP use, mask leak, residual respiratory events and flow limitation. Ninety‐one CPAP‐naive patients with newly diagnosed obstructive sleep apnea were followed for 1 week after treatment initiation. Mean CPAP daily use during the first week was 3.4 ± 2.7 h, with significantly lower use observed in black than non‐black participants (2.7 versus 4.4 h, respectively, P = 0.002). Less intimacy with partners caused by CPAP was the only treatment side effect correlated with CPAP use (r = −0.300, P = 0.025). Reduced CPAP use during the first week was associated simultaneously with being black, higher residual apnea–hypopnea index and the treatment side effect of less intimacy with partners. The three factors together accounted for 25.4% of the variance in the CPAP use (R2 = 0.254, P < 0.01). These data suggest the need to assess the impact of CPAP on intimacy and troubleshooting aspects of the treatment that interfere with sexual relationships. Assessing the presence of residual respiratory events may be important in promoting CPAP adherence. The association of race and CPAP use needs to be explored further by including more socioeconomic information.

Screening for Severe Obstructive Sleep Apnea Syndrome in Hypertensive Outpatients

The authors attempted to validate a 2‐stage strategy to screen for severe obstructive sleep apnea syndrome (s‐OSAS) among hypertensive outpatients, with polysomnography (PSG) as the gold standard. Using a prospective design, outpatients with hypertension were recruited from medical outpatient clinics. Interventions included (1) assessment of clinical data; (2) home sleep testing (HST); and (3) 12‐channnel, in‐laboratory PSG. The authors developed models using clinical or HST data alone (single‐stage models) or clinical data in tandem with HST (2‐stage models) to predict s‐OSAS. For each model, area under receiver operating characteristic curves (AUCs), sensitivity, specificity, negative likelihood ratio, and negative post‐test probability (NPTP) were computed. Models were then rank‐ordered based on AUC values and NPTP. HST used alone had limited accuracy (AUC=0.727, NPTP=2.9%). However, models that used clinical data in tandem with HST were more accurate in identifying s‐OSAS, with lower NPTP: (1) facial morphometrics (AUC=0.816, NPTP=0.6%); (2) neck circumference (AUC=0.803, NPTP=1.7%); and Multivariable Apnea Prediction Score (AUC=0.799, NPTP=1.5%) where sensitivity, specificity, and NPTP were evaluated at optimal thresholds. Therefore, HST combined with clinical data can be useful in identifying s‐OSAS in hypertensive outpatients, without incurring greater cost and patient burden associated with in‐laboratory PSG. These models were less useful in identifying obstructive sleep apnea syndrome of any severity.

Hits and misses: screening commercial drivers for obstructive sleep apnea using guidelines recommended by a joint task force.

Objective:To evaluate joint task force criteria-based screening for severe obstructive sleep apnea (s-OSA) in commercial drivers. Methods:Among a community-based cohort of licensed commercial vehicle drivers, we assessed utility of the joint task force criteria. We conducted full, 14-channel overnight polysomnography in all drivers, defining s-OSA as an apnea–hypopnea index of 30 or more per hour. Results:One hundred of 104 drivers with successful polysomnography studies were predominantly obese (median body mass index = 32.8 kg/m2; interquartile range = 26.8 to 37.4) and had a median apnea—hypopnea index of 20.6 per hour (interquartile range = 10.0 to 34.2). Examination-based criteria were more effective (sensitivity = 80%; negative posttest probability [nPTP] = 17%) than symptom-based criteria (sensitivity = 63%; nPTP = 23%). Examination and symptom-based criteria combined had high sensitivity (97%) and low nPTP (7%), but poor specificity (19%). Conclusions:Examination-based criteria missed 20% of s-OSA cases. Combining examination with confidentially reported symptoms improved sensitivity but required confirmatory polysomnography in 86%, supporting universal screening of all drivers.