Socioeconomic Factors and Adherence to CPAP: The Population-Based Course of Disease in Patients Reported to the Swedish CPAP Oxygen and Ventilator Registry Study.

BACKGROUND: Early identification of poor adherence to CPAP treatment is of major clinical importance to optimize treatment outcomes in patients with OSA. RESEARCH QUESTION: How do socioeconomic factors influence CPAP adherence? STUDY DESIGN AND METHODS: Nationwide, population-based cohort study of patients with OSA receiving CPAP treatment reported to the Swedish quality registry Swedevox between 2010 and 2018 was cross-linked with individual socioeconomic data from Statistics Sweden. Socioeconomic factors associated with CPAP adherence were identified using a multivariate linear regression model, adjusted for age and sex. RESULTS: In total, 20,521 patients were included: 70.7% men; mean age ± SD, 57.8 ± 12.2 years; BMI, 32.0 ± 6.1 kg/m2; apnea-hypopnea index, 36.9 ± 22.1; Epworth Sleepiness Scale, 10.4 ± 5.0; and median nocturnal CPAP use, 355 min (interquartile range, 240-420 min). Adherence after 1.3 ± 0.8 years of CPAP use was significantly (all P < .001) associated with civil status (married vs unmarried: +20.5 min/night), education level (high, ≥ 13 years vs low, ≤ 9 years: +13.2 min/night), total household income (highest/third/second vs lowest quartile: +15.9 min/night, +10.4 min/night, and +6.1 min/night, respectively), and country of birth (born in Sweden with one native parent/born in Sweden with two native parents vs being born abroad: +29.0 min/night and +29.3 min/night, respectively). INTERPRETATION: Civil status, educational level, household income, and foreign background predict CPAP adherence in a clinically significant manner and should be considered when treating OSA with CPAP.

Validation of the Swedevox registry of continuous positive airway pressure, long-term mechanical ventilator and long-term oxygen therapy.

BACKGROUND: The Swedish Registry of Respiratory Failure (Swedevox) collects nationwide data on patients starting continuous positive airway pressure (CPAP) treatment, long-term mechanical ventilator (LTMV) and long-term oxygen therapy (LTOT). We validated key information in Swedevox against source data from medical records. METHODS: This was a retrospective validation study of patients starting CPAP (n=175), LTMV (n=177) or LTOT (n=175) across seven centres 2013-2017. Agreement with medical record data was analysed using differences in means (sd) and proportion (%) of a selection of clinically relevant variables. Variables of interest included for CPAP: apnoea-hypopnoea index (AHI), height, weight, body mass index (BMI) and Epworth Sleepiness Scale (ESS) score; for LTMV: date of blood gas, arterial carbon dioxide tension (P aCO2 ) (breathing air), weight and diagnosis group; and for LTOT: blood gases breathing air and oxygen, spirometry and main diagnosis. RESULTS: Data on CPAP and LTOT had very high validity across all evaluated variables (all <5% discrepancy). For LTMV, variability was higher against source information for P aCO2 (>0.5 kPa in 25.9%), weight (>5 kg in 47.5%) and diagnosis group. Inconsistency was higher for patients starting LTMV acutely versus electively (P aCO2 difference >0.5 kPa in 36% versus 21%, p<0.05, respectively). However, there were no signs of systematic bias (mean differences close to zero) across the evaluated variables. CONCLUSION: Validity of Swedevox data, compared with medical records, was very high for CPAP, LTMV and LTOT. The large sample size and lack of systematic differences support that Swedevox data are valid for healthcare quality assessment and research.

Course of DISease In patients reported to the Swedish CPAP Oxygen and VEntilator RegistrY (DISCOVERY) with population-based controls.

PURPOSE: Chronic hypoxic and hypercapnic respiratory failure and obstructive sleep apnoea (OSA) are chronic diseases associated with decreased quality of life and increased mortality. The rationale behind the set up the retrospective nationwide DISCOVERY cohort was to study several questions including disease course and risk factors for incident disease, impaired quality of life, hospitalisation risk and mortality in patients with chronic respiratory failure with long-term oxygen therapy (LTOT), long-term mechanical ventilation (LTMV) and obstructive sleep apnoea (OSA) on treatment with continuous positive airway pressure (CPAP). PARTICIPANTS AND SETTINGS: Data from the national quality registry for respiratory insufficiency and sleep apnoea (Swedevox) and a population-based control group from Statistics Sweden were merged with governmental registries, the Swedish Cancer Registry, the Swedish Cause of Death Registry, the Swedish Drug registry, the Swedish National Patient Registry and the Swedish Dental Health Registry and with national quality registries for diabetes, rheumatic diseases (Swedish Rheumatology Quality Registry), stroke (RiksStroke), heart failure (RiksSvikt), acute heart infarction care (SwedeHeart) and intensive care (SIR) and with socioeconomic data from Statistics Sweden (SCB). FINDINGS TO DATE: The cohort comprises 25 804 unique patients with LTOT since 1987 (54.1% females, age 73.3±9.8 years, body mass index (BMI) 26.6±6.5 kg/m2), 8111 with LTMV since 1996 (48.6% women, age 60.6±16.9 years, BMI 32.9±10.8 kg/m2), 65 809 with OSA on CPAP since 2010 (29.5% women, age 57.2±12.5 years, BMI 31.9±6.2 kg/m2) and 145 224 persons in a population-based control group from same time span up to March 2018 (51.7% women, age 49.9±20.4 year, BMI 24.9±4.0 years). FUTURE PLANS: In patients with chronic respiratory failure and sleep apnoea important questions regarding comorbidity burden, hospitalisation rate, mortality and treatment outcomes are still unexplored to a large extent. The DISCOVERY cohort will provide unique opportunities by its size and comprehensiveness to fill this clinically relevant gap of knowledge.

Factors influencing adherence to continuous positive airway pressure treatment in obstructive sleep apnea and mortality associated with treatment failure - a national registry-based cohort study.

OBJECTIVES: Adherence to continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA) is crucial. Our aim was to identify protective and risk factors against the discontinuation of CPAP treatment in patients with OSA and to estimate the mortality risk in those who were non-adherent to CPAP therapy. METHODS: This was a registry-based cohort study from 37 centers across Sweden with OSA patients on CPAP in the Swedevox Swedish national registry between July 2010 and March 2017. RESULTS: In 16,425 patients (70.8% men) with complete follow-up data after 1.2 ± 0.8 years the adjusted relative risk ratio (aRRR) for the discontinuation of CPAP was 0.57 (95% confidence interval (CI) 0.50-0.65) for use of humidifier, 0.87 (95% CI 0.82-0.92) for increasing age per 10 years, 0.80 (95% CI 0.77-0.83) for increasing apnea hypopnea index (AHI) per 5 units/hour, and 0.96 (95% CI 0.95-0.97) per increased unit on the Epworth Sleepiness Scale (ESS). Increasing BMI was associated with increased adherence up to BMI 35. Women and patients with hypertension ran an increased risk of discontinuing CPAP treatment, aRRR 1.28 (95% CI 1.12-1.46) and 1.24 (95% CI 1.12-1.42) respectively. The adjusted hazard ratio (HR) for mortality was 1.74 (95% CI 1.32-2.28) among those who did not adhere to CPAP (median follow-up period 2.4 years after the one year adherence evaluation). CONCLUSION: Use of humidifier is associated with greater adherence to CPAP treatment. Other factors predicting adherence are increasing age, more severe OSA and overweight up to BMI 35, whereas female gender and coexisting hypertension are risk factors for discontinuation of CPAP. Failure to adhere to CPAP is associated with increased mortality.

A nationwide structure for valid long-term oxygen therapy: 29-year prospective data in Sweden.

BACKGROUND: Long-term oxygen therapy (LTOT) improves prognosis in COPD with severe hypoxemia. However, adherence to criteria for eligibility and quality of LTOT is often insufficient and varies between countries. The aim of this study was to evaluate a national structure for prescription and management of LTOT over three decades in Sweden. METHODS: The study was a prospective, population-based study of 23,909 patients on LTOT from 1987 to 2015 in the Swedish National Register of Respiratory Failure (Swedevox). We assessed the prevalence, incidence, and structure of LTOT; completeness of registration in Swedevox; and validity of prescription and management of LTOT in Sweden according to seven published quality indicators. RESULTS: LTOT was prescribed by 48 respiratory or medicine units and managed mainly by specialized oxygen nurses. Swedevox had a stable completeness of 85% of patients starting LTOT since 1987. The national incidence of LTOT increased from 3.9 to 14.7/100,000 inhabitants over the time period. In 2015, 2,596 patients had ongoing therapeutic LTOT in the registry, a national prevalence of 31.6/100,000. Adherence to prescription recommendations and fulfillment of quality criteria was stable or improved over time. Of patients starting LTOT in 2015, 88% had severe hypoxemia (partial pressure of arterial oxygen [PaO2] <7.4 kPa) and 97% had any degree of hypoxemia (PaO2 <8.0 kPa); 98% were prescribed oxygen ≥15 hours/day or more; 76% had both stationary and mobile oxygen equipment; 75% had a mean PaO2 >8.0 kPa breathing oxygen; and 98% were non-smokers. CONCLUSION: We present a structure for prescription, management, and follow-up of LTOT. The national registry effectively monitored adherence to prescription recommendations and most likely contributed to improved quality of care.

Gender differences in patients starting long-term home mechanical ventilation due to obesity hypoventilation syndrome.

BACKGROUND AND OBJECTIVES: Obesity hypoventilation syndrome (OHS) is often diagnosed late. The aim of this study was to analyse gender differences at initiation of long-term mechanical ventilation (LTMV) in patients with (OHS), to analyse gender differences in treatment effect and to study how the prescription of LTMV due to OHS has changed over time. METHODS: Data on patients on LTMV due to OHS between 1996 and 2014 were obtained from Swedevox, a nationwide health quality registry of patients on LTMV in Sweden. RESULTS: When starting LTMV, women were generally older (age 64.4 ± 11.2 vs. 60.1 ± 12.1 years, p < 0.001), more obese (BMI 43.0 ± 8.2 vs. 41.5 ± 7.9 kg/m2, p < 0.001), more hypoxic (PaO2 7.6 ± 1.5 vs. 7.9 ± 1.6 kPa, p = 0.001), had more hypercapnia (PaCO2 7.2 ± 1.3 vs. 6.9 ± 1.3 kPa, p = 0.001), had higher base excess (6.9 ± 4.1 vs. 5.8 ± 4.7 kPa, p < 0.001) and more frequently started LTMV in a non-elective situation (43.2% vs. 37.5%, p = 0.026) than men. Improvement of arterial blood gas values or in age-adjusted mortality at one-year follow-up did not differ. During the study period, the age of patients at the initiation of LTMV rose by 3.4 years/decade (P = 0.001) in women and with 1.9 years/decade (P = 0.048) in men but there were no significant changes in BMI (P = 0.425). CONCLUSIONS: Diagnosis of OHS is more delayed in women and as a consequence the disease is more advanced when diagnosed. In spite of this, there is no gender difference in survival rate in patients with OHS treated with LTMV. More and older patients with OHS nowadays gain access to LTMV.

Hypo- and hypercapnia predict mortality in oxygen-dependent chronic obstructive pulmonary disease: a population-based prospective study.

BACKGROUND: The prognostic role of the arterial blood gas tension of carbon dioxide (PaCO2) in severe Chronic Obstructive Pulmonary Disease (COPD) remains unknown. The aim of this study was to estimate the association between PaCO2 and mortality in oxygen-dependent COPD. METHODS: National prospective study of patients starting long-term oxygen therapy (LTOT) for COPD in Sweden between October 1, 2005 and June 30, 2009, with all-cause mortality as endpoint. The association between PaCO2 while breathing air, PaCO2 (air), and mortality was estimated using Cox regression adjusted for age, sex, arterial blood gas tension of oxygen (PaO2), World Health Organization performance status, body mass index, comorbidity, and medications. RESULTS: Of 2,249 patients included, 1,129 (50%) died during a median 1.1 years (IQR 0.6-2.0 years) of observation. No patient was lost to follow-up. PaCO2 (air) independently predicted adjusted mortality (p < 0.001). The association with mortality was U-shaped, with the lowest mortality at approximately PaCO2 (air) 6.5 kPa and increased mortality at PaCO2 (air) below 5.0 kPa and above 7.0 kPa. CONCLUSION: In oxygen-dependent COPD, PaCO2 (air) is an independent prognostic factor with a U-shaped association with mortality.

Long-term effects of continuous positive airway pressure treatment on sexuality in female patients with obstructive sleep apnea.

INTRODUCTION: Results from a previous study showed that sexuality was negatively affected in females with untreated obstructive sleep apnea (OSA). Data are sparse on the long-term effects of nocturnal continuous positive airway pressure (CPAP) treatment on sexual difficulties and sexual distress in female patients with OSA. AIM: The aim of the present study was to investigate the effects after 1 year of CPAP treatment on sexual difficulties, sexual distress, and manifest sexual dysfunction in female patients with OSA. The effect of CPAP on life satisfaction was also investigated. METHODS: Fifty-four therapy-compliant, female patients (age 22-71) received a survey before and after 1 year of nocturnal CPAP treatment. The questions on this survey were drawn from three self-administered questionnaires: two on sexuality and one on life satisfaction. The results were compared with a population sample. The Epworth Sleepiness Scale was used for assessment of daytime sleepiness. MAIN OUTCOME MEASURES: The Female Sexual Function Index, Female Sexual Distress Scale, Manifest Female Sexual Dysfunction, four questions from Life Satisfaction 11, and the Epworth Sleepiness Scale were all used to measure outcome. RESULTS: In total, 44 patients responded to the survey (81% response rate). The results were a significant, positive change in manifest female sexual dysfunction, but no significant changes in isolated sexual difficulties or sexual distress. Daytime sleepiness significantly decreased after 1 year. The results from the Life Satisfaction 11 questionnaire remained unchanged after 1 year. CONCLUSIONS: After 1 year of CPAP treatment, female patients with OSA reported reduced manifest sexual dysfunction. However, it cannot be concluded if this result is due to CPAP treatment alone. Furthermore, reduced daytime tiredness was found in the surveyed population. CPAP treatment, per se, does not seem to affect partner relationships. Petersen M, Kristensen E, Berg S, and Midgren B. Long-term effects of continuous positive airway pressure treatment on sexuality in female patients with obstructive sleep apnea. Sex Med 2013;1:62-68.

Sexual function in male patients with obstructive sleep apnoea after 1 year of CPAP treatment.

OBJECTIVE: Our objective was to investigate what impact 1 year of effective nocturnal continuous positive airway pressure (CPAP) treatment had on general and functional aspects of sexuality in male patients with a confirmed diagnosis of obstructive sleep apnoea (OSA). METHODS: Before and after 1 year of CPAP treatment, a total of 207 CPAP-compliant male patients (age 26­77) received a survey with questions drawn from two self-administered questionnaires on sexuality ­ Life Satisfaction 11 (LiSat-11) and brief sexual function inventory (BSFI). For assessment of daytime sleepiness, we used the Epworth sleepiness scale (ESS). RESULTS: Response rate was 76%. We found no significant changes in satisfaction with relation to partner or life as a whole, but satisfaction with sexual life (LiSat-11) and both general and functional aspects of sexuality (BSFI) were significantly improved after 1 year of CPAP treatment. ESS score decreased significantly after 1 year of CPAP treatment. CONCLUSION: One year of CPAP treatment improves all aspects of sexual function in male patients with OSA. Our data indirectly suggest that organic factors are the most likely explanation to these improvements.

Sexual function in female patients with obstructive sleep apnea.

INTRODUCTION: Obstructive sleep apnea is defined as repetitive (≥5/hour) partial or complete cessation of breathing during sleep. Whereas obstructive sleep apnea is often considered to be associated with sexual problems in men, studies concerning effects of obstructive sleep apnea on female sexual function and distress are sparse. AIM: To investigate sexual dysfunction and sexual distress in female patients with obstructive sleep apnea and to determine which factors are of importance for their sexual function. METHODS: We investigated 80 female patients (ages 28-64) admitted to a sleep laboratory and who after investigation received a diagnosis of obstructive sleep apnea. All subjects answered questions drawn from three self-administered questionnaires on sexuality. The results were compared with a population sample (N=240). MAIN OUTCOME MEASURE: Data from nocturnal respiratory recordings. Female Sexual Function Index, Female Sexual Distress Scale and four questions from Life Satisfaction-11 (Lisat-11). RESULTS: Female Sexual Function Index indicated that obstructive sleep apnea patients were at a higher risk for having sexual difficulties. Female Sexual Distress Scale showed significantly more sexual distress in the obstructive sleep apnea group. Manifest Female Sexual Dysfunction (combined data from Female Sexual Function Index and Female Sexual Distress Scale) showed that female patients with obstructive sleep apnea also had more sexual dysfunction. Severity of sleep apnea was, however, not related to any of these indices but consumption of psychopharmaca was. In Lisat-11, we found that obstructive sleep apnea females scored lower than women in the population sample regarding life as a whole but not regarding domains of closeness. CONCLUSIONS: This study indicates that sexuality of women with untreated obstructive sleep apnea is negatively affected compared with a female population sample. This was not related to severity of obstructive sleep apnea, whereas psychopharmaca may act as an important confounder.

Sexual function in male patients with obstructive sleep apnoea.

OBJECTIVE: Our objective was to investigate general and functional aspects of sexuality in male patients with a confirmed diagnosis of obstructive sleep apnoea (OSA) and compare the results with normative data. MATERIALS AND METHODS: We investigated 308 male patients (age 30-69) admitted to a sleep laboratory and receiving a diagnosis of OSA, using questions drawn from two self-administered questionnaires on sexuality [Fugl-Meyer Life satisfaction checklist (LiSat) and Brief Sexual Function Inventory (BSFI)]. RESULTS: We found that both general (Fugl-Meyer LiSat) and functional (BSFI) aspects of sexuality were worse in patients with (untreated) OSA when compared with normative data. Both aspects were dependent on age, obesity, social factors and concomitant medication but not on the severity of OSA as reflected by the apnoea-hypopnoea index or subjective sleepiness. CONCLUSION: We conclude that although sexual dysfunction is more prevalent in OSA patients than in the general population, it is a complex problem relating more to age, obesity, social factors and comorbidity than to the severity of OSA.

Cheyne-Stokes respiration is not related to quality of life or sleepiness in heart failure.

BACKGROUND AND AIMS: The effects of central sleep apnea in Cheyne-Stokes respiration on sleep-related symptoms and quality of life are not very well established. We aimed to investigate whether Cheyne-Stokes respiration is related to health-related quality of life. We also studied the impact on daytime sleepiness and nocturnal dyspnea. METHODS: Included were 203 consecutive patients, stabilized following in-hospital treatment for decompensated congestive heart failure. They underwent overnight cardiorespiratory sleep apnea recordings in hospital and answered a set of questions on symptoms and health-related quality of life questionnaires in the form of the Nottingham Health Profile and the Minnesota Living with Heart Failure Questionnaire. After excluding seven patients with predominantly obstructive apneas and 14 with insufficient recordings, 182 patients were included in the final analysis. RESULTS: One third of the patients had an apnea-hypopnea index (AHI) of >30. Falling asleep in front of the television was the only symptom related to (AHI). Nocturnal dyspnea, daytime sleepiness, generic quality of life or disease-specific quality of life were not related to AHI. CONCLUSIONS: Cheyne-Stokes respiration was not associated with health-related quality of life, daytime sleepiness or nocturnal dyspnea among patients stabilized following treatment for congestive heart failure.

Qualify of life and palliation predict survival in patients with chronic alveolar hypoventilation and nocturnal ventilatory support.

OBJECTIVES: Non-invasive positive pressure ventilation (NPPV) improves health-related quality of life (HRQL) in patients with chronic alveolar hypoventilation (CAH). We studied the prognostic impact of HRQL on survival in relation to clinical factors. PATIENTS: Forty-four patients with CAH due to post-polio (12), scoliosis (11), post-tb (17) or other diagnoses (4) who received nocturnal NPPV were prospectively studied during 6-10 years. MEASUREMENTS: Blood gases and HRQL were analysed at baseline and after 9 months and after 8 years. HRQL was evaluated with measures of functioning (SIP), emotional well-being (HADS and MACL), and global QL. RESULTS: Blood gases and HRQL measures improved during NPPV. The overall 5-year survival rate was 73%. In multivariate survival analysis, a diagnosis of post-polio and low baseline SIP physical index scores, indicating low levels of physical dysfunction, predicted longer survival (P = 0.02, respectively). Similarly, palliation of physical dysfunction and preserved or improved global QL by 9 months were associated with longer overall survival (P = 0.009 and P = 0.001, respectively; multivariate Cox regression). CONCLUSION: Seventy-three percent of patients treated for CAH with NPPV survived more than 5 years. Diagnosis and self-rated physical functioning at pre-treatment were related to survival, as were major improvements in physical functioning and global QL during NPPV.

Increased survival with mechanical ventilation in posttuberculosis patients with the combination of respiratory failure and chest wall deformity.

BACKGROUND: Patients who have had tuberculosis are at risk for respiratory failure with hypercapnea from chest wall deformity and hypoxia from pulmonary sequelae. The combination of hypercapnea and hypoxia justifies both mechanical ventilation and oxygen therapy as treatment options. We aimed to study which treatment mode is associated with the best survival in patients with the combination of respiratory failure and chest wall deformity from tuberculosis. METHODS: Swedish patients starting oxygen therapy or mechanical ventilation between 1996 and 2004 due to the combination of respiratory failure and chest wall deformity from tuberculosis were eligible for conclusion. They were followed up prospectively until October 2006, with death as the primary outcome. RESULTS: A cohort of 188 patients was included. Eighty-five patients received mechanical ventilation, and 103 received oxygen therapy alone. No patients were excluded, and no patients were unavailable for follow-up. Mechanical ventilation was associated with a significantly better survival than oxygen therapy alone, even after adjustments for age, gender, concomitant respiratory disease, blood gas tensions, and vital capacity, with an adjusted hazard risk of death of 0.35 (95% confidence interval, 0.17 to 0.70). CONCLUSION: Patients with the combination of respiratory failure and chest wall deformity from tuberculosis had a significantly better survival when treated with home mechanical ventilation than with long-term oxygen therapy alone. We recommend home mechanical ventilation with or without supplementary oxygen as the first choice of treatment for these patients.

Impact of home mechanical ventilation on health-related quality of life in patients with chronic alveolar hypoventilation: a prospective study.

BACKGROUND: Nocturnal ventilatory support by nasal positive pressure ventilation (NPPV) is an established treatment method in patients with chronic alveolar hypoventilation (CAH). The knowledge about its long-term effects on health-related quality of life (HRQL) is limited. METHODS: In a prospective, longitudinal, single-strand study, patients with CAH caused by non-COPD conditions, consecutively recruited among referral patients in three Swedish university hospital pulmonary departments, were examined at baseline and after 9 months (n = 35) and 8 years (n = 11) on NPPV treatment. Both volume pre-set and pressure pre-set ventilators were used. Patients completed a battery of condition-specific and generic HRQL questionnaires at baseline and follow-up. Spirometry and blood gases were measured. Compliance with treatment, side effects and patient satisfaction were evaluated. RESULTS: After 9 months of NPPV, improvements were seen primarily not only in sleep-related domains, but also in emotional behaviour, ambulation and sleep/rest functioning as measured with the Sickness Impact Profile (SIP). Improvements in sleep-related symptoms were related to effectiveness in ventilation, evaluated by morning PaCO(2), and remained by 8 years. Mental well-being was stable over time, while emotional distress improved by 8 years. Satisfaction with treatment was high in spite of frequent side effects. CONCLUSION: NPPV improves HRQL, particularly in condition-specific areas. Improvements are related to effectiveness in ventilation. Side effects are common, but compliance is good and patient satisfaction is high.

Survival of patients on home mechanical ventilation: a nationwide prospective study.

Home mechanical ventilation (HMV) is increasingly used as a therapeutic option to patients with symptomatic chronic hypoventilation. There is, however, a paucity of solid data on factors that could affect prognosis in patients on home ventilation. In the present study, our aim was to study several factors in these patients with potential influence on survival. We examined 1526 adult patients from a nationwide HMV register to which data had been reported prospectively for 10 years. The patients constituted a broad diagnostic spectrum and the primary outcome in this study was death. We found by far the poorest survival rate in the ALS patients with only 5% alive after 5 years. Among the other patient groups the survival pattern was more uniform and the scoliosis, polio and Pickwick patients presented the best survival rate, after 5 years being around 75%. No factors were associated with a greater hazard for death in the ALS patients; in the non-ALS patients, however, negative predictors for survival were age, concomitant use of oxygen therapy, tracheostomy ventilation and start of ventilatory support in an acute clinical setting. Center size or county specific home ventilation treatment prevalence did not affect survival. In conclusion, in a large material of patients on HMV we found by far the poorest survival in the ALS patients. In the non-ALS patients a number of patient-related factors affected survival, while the size of the treating center or the regional treatment prevalence did not.