We conducted a study of the prevalence of sleep-disordered breathing in subjects derived from a random sample of the population. A total of 2,202 subjects 35 to 69 yr of age were approached. Four hundred forty-one answered a questionnaire concerning their sleep symptoms, general health, and habits such as alcohol consumption, and they were monitored for sleep-disordered breathing (SDB). The sample was biased in favor of snorers and those with other subjective sleep complaints. Fifty-six percent of the subjects were men. Of the 441 subjects 79 (17.9%) had SDB (more than 15 episodes of apnea or hypopnea per hour: respiratory distress index [RDI] > or = 15), 289 were snorers but had RDI < 15, and 73 were nonsnorers. The prevalence of SDB in this sample was therefore at least 3.6% (79 of 2,204). The minimum prevalence in men was 5.7%, and in women it was 1.2%. Logistic regression identified only male sex as an independent predictor of snoring without SDB (adjusted odds ratio [OR], 3.24; 95% CI, 1.33 to 7.82), body mass index (adjusted OR for an increase of 5 kg/m2, 0.95; 95% CI, 0.85 to 1.05), and alcohol consumption (adjusted OR for an increase of 10 g/day, 1.05; 95% CI, 0.84 to 1.37) were not significant predictors of snoring. The independent predictors of SDB among snorers were age (adjusted OR for an increase of 5 yr, 1.26; 95% CI, 1.08 to 1.47) and neck circumference (adjusted OR for an increase of 2 cm, 1.53; 95% CI, 1.16 to 2.00).(ABSTRACT TRUNCATED AT 250 WORDS)

In order to determine whether measurement of arterial oxygen saturation (SaO2) could identify patients with obstructive sleep apnea (OSA), 98 consecutive patients referred for assessment of snoring and/or daytime somnolence were assessed clinically and then underwent both unsupervised oximetry in their homes and formal polysomnography. Clinical assessment identified patients with an apnea+hypopnea index (AHI) > or = 15 events per hour with a sensitivity of 79% and a specificity of 50%. Home oximetry analyzed by counting the number of arterial oxygen desaturations recorded was inferior to clinical assessment. For desaturations of 2% or more from baseline, desaturation index (DI) > or = 15 per hour identified patients with AHI > or = 15 with sensitivity 65% and specificity 74%; for 3% desaturations, sensitivity was 51% and specificity 90%; and for 4% desaturations, sensitivity was 40% and specificity 98%. From the oximetry data, the percentage of time spent at SaO2 below 90% (CT90) was also calculated. CT90 > or = 1% identified patients with AHI > or = 15 with sensitivity 93% and specificity 51%; for patients with AHI > or = 15 ultimately given nasal continuous positive airway pressure (CPAP), the sensitivity of a CT90 > or = 1% was 100%. We concluded that home oximetry with CT90 < 1% practically excludes clinically significant OSA. Conversely, home oximetry with DI > or = 15 for 4% desaturations makes OSA likely: the positive predictive value for OSA is 83% if the pretest probability of OSA is 30% and over 90% if the pretest probability is at least 50%.

Four hundred forty-one subjects 34 to 69 yr of age were recruited from a random sample of the community. The sample was biased in favor of men, snorers, and subjects with subjective sleep complaints. They answered a questionnaire and were monitored in their homes for sleep-disordered breathing (SDB). This report concerns the presence of symptoms associated with the obstructive sleep apnea (OSA) syndrome in the subjects with SDB detected in this community sample. Most of the symptoms commonly recognized as occurring in OSA were associated with SDB in our sample: snoring that disturbed the sleep of other persons, reports of apnea, reports of gasping or choking sounds during sleep, and finding the bedclothes in disarray in the mornings had significant univariate associations with SDB. Nocturnal choking and morning headache were negatively associated with SDB. Excessive daytime somnolence (EDS) was reported by 41% of those with SDB, but it was also reported by 37% of snorers without SDB and by 37% of nonsnorers. We conclude that the symptoms seen in clinic patients with OSA also occur in subjects with SDB who have not presented for medical attention. Enumeration of these symptoms by questionnaire, however, is a poor test for OSA in the community. EDS was reported by a higher than expected proportion of subjects not affected by SDB, suggesting that causes of self-reported EDS other than SDB may be common.

Four hundred forty-one subjects 34 to 69 yr of age were recruited from a random sample of the community. They answered a questionnaire and were monitored in their homes for sleep-disordered breathing (SDB). This report concerns the association between observed SDB and arterial hypertension and vascular disease. Hypertension was defined as self-report of a diagnosis of hypertension made by a physician, current treatment for hypertension, or a systolic pressure greater than 150 mm Hg or a diastolic pressure greater than 90 mm Hg. Coronary artery disease was defined by self-report of angina or myocardial infarction of "heart attack." There were few cases of stroke or claudication, and a category of "occlusive vascular disease" was defined by self-report of coronary artery disease or of "blocked arteries" or stroke. Subjects were classified as snorers (n = 289) or nonsnorers (n = 73) by self-report of regular snoring, and as having SDB (n = 79) if more than 15 abnormal respiratory events were recorded per hour of recording. There were significant increases in the prevalence of hypertension, coronary artery disease, and occlusive vascular disease from nonsnorers (26, 7, and 10%, respectively) through snorers (39, 12, and 17%) to subjects with SDB (57, 20, and 28%). The crude odds ratio for SDB versus nonsnorers was 3.8 (95% CI, 1.9 to 7.5) for hypertension, 3.5 (1.2 to 10.0) for coronary artery disease, and 3.7 (1.5 to 9.1) for occlusive vascular disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Background -Ventilatory failure is a well recognised complication of patients who have had a thoracoplasty for tuberculosis, but there are few data regarding the value of long term non-invasive assisted ventilation in this situation. Methods -Thirty two patients who had had a thoracoplasty 20-46 years previously and who had developed respiratory failure were treated with nocturnal cuirass assisted ventilation or nasal positive pressure ventilation. Their survival and changes in arterial blood gases, nocturnal oximetry, and pulmonary function tests were assessed. Results -The actuarial survival rates at one, three, five, and seven years after starting treatment were 91%, 74%, 64%, and 55%, respectively. Only seven of the 13 deaths were directly attributable to chronic respiratory or cardiac failure. The arterial P02, Pco2, mean nocturnal oxygen saturation, vital capacity, and maximal inspiratory and expiratory pressures had all improved at the time ofthe initial posttreatment assessment (mean 12 days after starting treatment), but no subsequent improvements were seen after up to 48 months of follow up. Neither survival nor physiological improvements were correlated with the patients' age, the interval since thoracoplasty, or the pretreatment arterial blood gas tensions or results of pulmonary function tests. Conclusions -These results show that, even when ventilatory failure has developed, the prognosis with non-invasive assisted ventilation is good and the physiological abnormalities can be partially reversed. Patients who develop respiratory failure after a thoracoplasty should be considered for this type of long term domiciliary treatment. (Thorax 1994;49:915-919) Treatment by surgical collapse, especially thoracoplasty, played an important part in the management of pulmonary tuberculosis before the advent of effective antituberculous chemotherapy. Thoracoplasty causes a restrictive defect as a consequence of pleural thickening, thoracic cage deformity, and secondary scoliosis.lA Airflow obstruction is also common in these patients and, when severe, is associated with hypoxia and hypercapnia.5 Many patients who were treated with a thoracoplasty now have respiratory symptoms and some are at risk of developing respiratory failure.7 Domiciliary assisted ventilation is a well established treatment for respiratory failure in patients with neuromuscular and chest wall disorders, but there is little information about the outcome of this treatment in patients who have had a thoracoplasty. The aims of this study were to document the physiological results and survival of thoracoplasty patients who have been treated with assisted ventilation. MethodsThirty two patients who had undergone thoracoplasty were established on assisted ventilation at our centre between December 1983 and September 1993. There were eight men and 24 women of mean age 62 3 (range 35-78) years. Sixteen had left thoracoplasties, 14 were right sided, and two had bilateral thoracoplasties. Most of the patients had also had an artificial pneu...