Thoracic Society of Australia and New Zealand clinical practice guideline on adult home oxygen therapy.

This Thoracic Society of Australia and New Zealand Guideline on the provision of home oxygen therapy in adults updates a previous Guideline from 2015. The Guideline is based upon a systematic review and meta-analysis of literature to September 2022 and the strength of recommendations is based on GRADE methodology. Long-term oxygen therapy (LTOT) is recommended for its mortality benefit for patients with COPD and other chronic respiratory diseases who have consistent evidence of significant hypoxaemia at rest (PaO2 ≤ 55 mm Hg or PaO2 ≤59 mm Hg in the presence of hypoxaemic sequalae) while in a stable state. Evidence does not support the use of LTOT for patients with COPD who have moderate hypoxaemia or isolated nocturnal hypoxaemia. In the absence of hypoxaemia, there is no evidence that oxygen provides greater palliation of breathlessness than air. Evidence does not support the use of supplemental oxygen therapy during pulmonary rehabilitation in those with COPD and exertional desaturation but normal resting arterial blood gases. Both positive and negative effects of LTOT have been described, including on quality of life. Education about how and when to use oxygen therapy in order to maximize its benefits, including the use of different delivery devices, expectations and limitations of therapy and information about hazards and risks associated with its use are key when embarking upon this treatment.

Long-term Telerehabilitation or Unsupervised Training at Home for Patients with Chronic Obstructive Pulmonary Disease: A Randomized Controlled Trial.

Rationale: Despite the benefits of pulmonary rehabilitation in chronic obstructive pulmonary disease (COPD), many patients do not access or complete pulmonary rehabilitation, and long-term maintenance of exercise is difficult. Objectives: To compare long-term telerehabilitation or unsupervised treadmill training at home with standard care. Methods: In an international randomized controlled trial, patients with COPD were assigned to three groups (telerehabilitation, unsupervised training, or control) and followed up for 2 years. Telerehabilitation consisted of individualized treadmill training at home supervised by a physiotherapist and self-management. The unsupervised training group performed unsupervised treadmill exercise at home. The control group received standard care. The primary outcome was the combined number of hospitalizations and emergency department presentations. Secondary outcomes included time free from the first event; exercise capacity; dyspnea; health status; quality of life; anxiety; depression; self-efficacy; and subjective impression of change. Measurements and Main Results: A total of 120 participants were randomized. The incidence rate of hospitalizations and emergency department presentations was lower in telerehabilitation (1.18 events per person-year; 95% confidence interval [CI], 0.94-1.46) and unsupervised training group (1.14; 95% CI, 0.92-1.41) than in the control group (1.88; 95% CI, 1.58-2.21; P < 0.001 compared with intervention groups). Telerehabilitation and unsupervised training groups experienced better health status for 1 year. Intervention participants reached and maintained clinically significant improvements in exercise capacity. Conclusions: Long-term telerehabilitation and unsupervised training at home in COPD are both successful in reducing hospital readmissions and can broaden the availability of pulmonary rehabilitation and maintenance strategies.

Clinically important changes and adverse events with centre-based or home-based pulmonary rehabilitation in chronic respiratory disease: A systematic review and meta-analysis.

Objectives: To determine the proportion of people who achieve minimal clinically important differences (MCID) with centre-based or home-based pulmonary rehabilitation and to synthesise data on adverse events.Methods: Cochrane reviews and electronic databases were searched to identify randomised trials comparing centre-based to home-based pulmonary rehabilitation, or either model to usual care, in people with chronic respiratory disease. Primary outcomes were the proportion of participants achieving MCIDs in exercise capacity and disease-specific quality of life. Secondary outcomes were symptoms and adverse events. Cochrane Risk of Bias 1.0 and GRADE were used to assess the risk of bias and certainty of evidence respectively.Results: Forty-nine trials were eligible. Compared to usual care, a higher proportion of pulmonary rehabilitation participants achieved the MCID for exercise capacity (6MWT: 47% vs 20%, p = 0.11), dyspnoea (43% vs 29%, p = 0.0001), fatigue (48% vs 27%, p = 0.0002) and emotional function (37% vs 25%, p = 0.02), with all of these between group differences statistically significant except for exercise capacity. There were no differences between centre-based and home-based pulmonary rehabilitation in the proportion of participants who achieved MCIDs (34%- 58% across studies). Ninety percent of trials reported no adverse events. Certainty of evidence was low-to- moderate with all outcomes except for CRQ-mastery (centre-based vs home-based pulmonary rehabilitation, or pulmonary rehabilitation vs usual care in COPD), ESWT (pulmonary rehabilitation vs usual care in COPD) and 6MWT (pulmonary rehabilitation vs usual care in bronchiectasis) where evidence was very uncertain.Discussion: Clinically meaningful outcomes are achieved by similar proportions of participants in centre-based and home-based pulmonary rehabilitation, with few adverse events. Reporting of trial outcomes according to MCIDs is necessary for informed decision making regarding pulmonary rehabilitation models.

Thoracic Society of Australia and New Zealand Position Statement on Acute Oxygen Use in Adults: 'Swimming between the flags'.

Oxygen is a life-saving therapy but, when given inappropriately, may also be hazardous. Therefore, in the acute medical setting, oxygen should only be given as treatment for hypoxaemia and requires appropriate prescription, monitoring and review. This update to the Thoracic Society of Australia and New Zealand (TSANZ) guidance on acute oxygen therapy is a brief and practical resource for all healthcare workers involved with administering oxygen therapy to adults in the acute medical setting. It does not apply to intubated or paediatric patients. Recommendations are made in the following six clinical areas: assessment of hypoxaemia (including use of arterial blood gases); prescription of oxygen; peripheral oxygen saturation targets; delivery, including non-invasive ventilation and humidified high-flow nasal cannulae; the significance of high oxygen requirements; and acute hypercapnic respiratory failure. There are three sections which provide (1) a brief summary, (2) recommendations in detail with practice points and (3) a detailed explanation of the reasoning and evidence behind the recommendations. It is anticipated that these recommendations will be disseminated widely in structured programmes across Australia and New Zealand.

Substantial variation exists in spirometry interpretation practices for airflow obstruction in accredited lung function laboratories across Australia and New Zealand.

BACKGROUND: Spirometry forms the foundation investigation for the diagnosis and monitoring of common pulmonary conditions. However, potential variation in spirometry interpretation for airflow obstruction may impact subsequent clinical management. AIM: To audit spirometry interpretation practices for airflow obstruction in Thoracic Society of Australia and New Zealand accredited laboratories. METHODS: Thirty-nine accredited complex lung function laboratories were invited to participate in an online survey. The survey enquired about demographics, definition of lower limit of normal range for spirometry parameters, spirometric parameters used for identifying airflow obstruction, spirometric definition of airflow obstruction, definition of significant bronchodilator response and chosen spirometry reference equations. RESULTS: Thirty-six laboratories provided complete responses (response rate, 92%). To define the lower limit of normal, 26 of 36 used the 5th percentile, 7 of 36 used a fixed cut-off and 3 used other. Twenty-nine laboratories utilised forced expiratory volume in 1 s/forced vital capacity (FEV1 /FVC) as the sole parameter to identify airflow obstruction, 3 of 36 used FEV1 /FVC and FEF25-75% , and 4 used other. To define airflow obstruction, 25 of 36 laboratories used FEV1 /FVC < 5th percentile, 9 of 36 used a fixed cut-off (FEV1 /FVC < 0.7, 6/36; FEV1 /FVC < 0.8, 2/36; FEV1 /FVC < 0.75, 1/36) and 2 of 36 used other. Twenty-six laboratories defined a significant bronchodilator response as an increase of at least 200 mL and 12% in FEV1 and/or FVC, 9 of 36 used ≥200 mL and ≥ 12% increase in FEV1 only, and 1 used other criteria. Reference equations utilised for interpretation of spirometry data included: Quanjer 2012 Global Lung Initiative (16/36), the third National Health and Nutritional Examination Survey (8/36), European Community of Coal and Steel (8/36) and other (4/36). CONCLUSIONS: Significant heterogeneity in spirometry interpretation for airflow obstruction exists across Australian and New Zealand accredited lung function laboratories. Lack of standardisation may translate into clinically appreciable differences for the diagnosis and management of common respiratory conditions. Ongoing discussion regarding formal standardisation is required.

Domiciliary non-invasive ventilation post lung transplantation.

BACKGROUND AND OBJECTIVE: The benefits of domiciliary non-invasive ventilation (NIV) post lung transplantation (LTx) have not previously been described. This was a single-centre retrospective audit of patients requiring domiciliary NIV post-LTx. Our aim was to describe indications for NIV and outcomes in chronic lung allograft dysfunction (CLAD) and diaphragmatic palsy. METHODS: All patients requiring domiciliary NIV post-LTx between 2010 and June 2016 were assessed. NIV indications, respiratory function and patient outcomes were collected. RESULTS: Out of 488 LTx recipients, 20 patients were identified as requiring NIV over the 6.5-year study period. The most common indications for NIV were CLAD and diaphragmatic palsy. Hypercapnia improved significantly with NIV. Patient outcomes were poor with nine (45%) patients dying, four (20%) undergoing redo-LTx, four (20%) continuing domiciliary NIV and only three (15%) patients weaned off NIV. CONCLUSION: This is the first case series to describe the use of domiciliary NIV post-LTx. Patients commenced on NIV post-LTx had severely impaired lung function and severe hypercapnia. Patients with diaphragmatic palsy often recovered. The mortality rate was high in chronic allograft dysfunction.

Characteristics of patients who progress from bridging to long-term oxygen therapy.

BACKGROUND: Patients with persistent hypoxia following an acute hospital admission may be discharged with 'bridging' domiciliary oxygen as per criteria defined by the Thoracic Society of Australia and New Zealand. The need for continuous long-term oxygen therapy (LTOT) is then reassessed at a clinic review 1-2 months later. AIM: To describe the characteristics of patients discharged from an acute hospital admission with continuous short-term oxygen therapy (STOT), and subsequently to investigate for differences between subjects who proceeded to qualify for continuous LTOT versus those who were able to cease STOT at review. METHODS: This is a retrospective cohort study involving all subjects discharged from Alfred Health between 2011 and 2015 inclusive with bridging domiciliary oxygen. Multiple biochemical, physiological and demographic characteristics were collated and analysed. RESULTS: Of all patients prescribed continuous STOT at time of discharge, 47.3% qualified for LTOT at outpatient review. This cohort had a significantly lower PaO2 measurement at time of discharge, compared with those who no longer qualified. CONCLUSION: PaO2 at time of discharge provides a signal with the potential to identify who will require continuous LTOT following an acute hospital admission. Additionally, this study highlights the need to re-evaluate patients' oxygen requirements during a period of clinical stability.

A conceptual model: Redesigning how we provide palliative care for patients with chronic obstructive pulmonary disease.

ABSTRACTBackground:Despite significant needs, patients with chronic obstructive pulmonary disease (COPD) make limited use of palliative care, in part because the current models of palliative care do not address their key concerns. OBJECTIVE: Our aim was to develop a tailored model of palliative care for patients with COPD and their family caregivers. METHOD: Based on information gathered within a program of studies (qualitative research exploring experiences, a cohort study examining service use), an expert advisory committee evaluated and integrated data, developed responses, formulated principles to inform care, and made recommendations for practice. The informing studies were conducted in two Australian states: Victoria and South Australia. RESULTS: A series of principles underpinning the model were developed, including that it must be: (1) focused on patient and caregiver; (2) equitable, enabling access to components of palliative care for a group with significant needs; (3) accessible; and (4) less resource-intensive than expansion of usual palliative care service delivery. The recommended conceptual model was to have the following features: (a) entry to palliative care occurs routinely triggered by clinical transitions in care; (b) care is embedded in routine ambulatory respiratory care, ensuring that it is regarded as "usual" care by patients and clinicians alike; (c) the tasks include screening for physical and psychological symptoms, social and community support, provision of information, and discussions around goals and preferences for care; and (d) transition to usual palliative care services is facilitated as the patient nears death. SIGNIFICANCE OF RESULTS: Our proposed innovative and conceptual model for provision of palliative care requires future formal testing using rigorous mixed-methods approaches to determine if theoretical propositions translate into effectiveness, feasibility, and benefits (including economic benefits). There is reason to consider adaptation of the model for the palliative care of patients with other nonmalignant conditions.

The effect of positive expiratory pressure (PEP) therapy on symptoms, quality of life and incidence of re-exacerbation in patients with acute exacerbations of chronic obstructive pulmonary disease: a multicentre, randomised controlled trial.

BACKGROUND: Positive expiratory pressure (PEP) is a technique used to enhance sputum clearance during acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The impact of PEP therapy during acute exacerbations on clinically important outcomes is not clear. This study sought to determine the effect of PEP therapy on symptoms, quality of life and future exacerbations in patients with AECOPD. METHODS: 90 inpatients (58 men; mean age 68.6 years, FEV(1) 40.8% predicted) with AECOPD and sputum expectoration were randomised to receive usual care (including physical exercise)±PEP therapy. The Breathlessness, Cough and Sputum Scale (BCSS), St George's Respiratory Questionnaire (SGRQ) and BODE index (Body mass index, airflow Obstruction, Dyspnoea, Exercise tolerance) were measured at discharge, 8 weeks and 6 months following discharge, and analysed via linear mixed models. Exacerbations and hospitalisations were recorded using home diaries. RESULTS: There were no significant between-group differences over time for BCSS score [mean (SE) at discharge 5.2 (0.4) vs 5.0 (0.4) for PEP and control group, respectively; p=0.978] or SGRQ total score [41.6 (2.6) vs 40.8 (2.8) at 8 weeks, p=0.872]. Dyspnoea improved more rapidly in the PEP group over the first 8 weeks (p=0.006), however these benefits were not observed at 6 months. Exacerbations (p=0.986) and hospitalisations (p=0.359) did not differ between groups. CONCLUSIONS: We found no evidence that PEP therapy during AECOPD improves important short-term or long-term outcomes. There does not appear to be a routine role for PEP therapy in the management of such individuals.

Delayed diagnosis of Swyer-James-MacLeod syndrome.

Swyer-James-MacLeod Syndrome is a rare obliterative lung disease typically caused by childhood infection resulting in arrested pulmonary development. Imaging findings include unilateral hyperlucency on chest x-ray, and hyperlucency, hypovascularity and expiratory gas trapping on computed tomography. Recognition of abnormal imaging can lead to earlier diagnosis and institution of appropriate management.

Advance care planning education in pulmonary rehabilitation: A qualitative study exploring participant perspectives.

BACKGROUND: Advance care planning is considered to have an important role in the management of people with chronic lung disease; however, uptake in clinical practice remains limited. Participant acceptance of the inclusion of an advance care planning information session in pulmonary rehabilitation and maintenance programmes could support a practical solution. AIM: To evaluate the introduction of a structured group advance care planning information session from the perspective of participants in pulmonary rehabilitation and maintenance programmes. DESIGN: Prospective qualitative study with semi-structured interview transcripts analysed using iterative thematic analysis. SETTING/PARTICIPANTS: Participants in pulmonary rehabilitation and maintenance programmes at a tertiary metropolitan hospital and two affiliated community sites. RESULTS: Sixty-seven participants with a range of chronic lung diseases were interviewed with ages ranging from 39 to 88 years, forced expiratory volume in 1 s (FEV1) ranging from 18% to 130% predicted and 6-min walk distance ranging from 105 to 619 m. Sixteen participants (24%) had previously heard of advance care planning. Major themes were that participants valued the advance care planning information and thought pulmonary rehabilitation was an appropriate setting. The group education format was well accepted and perceived to have advantages over individual sessions. Participants were happy to receive the information from a non-medical facilitator. Non-attendees had usually missed the session for reasons unrelated to content. A small number of participants felt advance care planning was not appropriate for them, but all recognised its value for other participants. CONCLUSIONS: Participants in our pulmonary rehabilitation and maintenance programmes value the opportunity to participate in a structured, group-based advance care planning session. Consideration should be given to broader inclusion of advance care planning education into existing pulmonary rehabilitation and maintenance programmes for people with chronic respiratory disease.

Ambulatory Oxygen in Fibrotic Interstitial Lung Disease: A Pilot, Randomized, Triple-Blinded, Sham-Controlled Trial.

BACKGROUND: Despite a lack of evidence, ambulatory oxygen therapy is frequently prescribed for patients with interstitial lung disease (ILD) and exertional desaturation. Patients often prefer portable oxygen concentrators to oxygen cylinders. This study aimed to examine the feasibility of conducting a clinical trial of ambulatory oxygen delivered via portable concentrators in patients with ILD. RESEARCH QUESTION: Is it feasible to conduct a clinical trial of ambulatory oxygen delivered via portable concentrators in patients with ILD? STUDY DESIGN AND METHODS: In this randomized, triple-blinded, sham-controlled trial, 30 participants with ILD and isolated exertional desaturation to < 90% on 6-minute walk tests were randomized to 12-week ambulatory oxygen or air delivered via portable concentrators, with assessments performed at baseline and weeks 4, 12, and 18. Primary outcomes were trial feasibility and the change in 6-minute walk distance (6MWD) on room air at week 12. RESULTS: Study recruitment was completed within 18 months, with six withdrawals. Participant blinding was successful, with the Bang's Blinding Index being 0 (95% CI, -0.40 to 0.40) for the oxygen group and 0 (95% CI, -0.42 to 0.42) for the sham group. No significant difference in 6MWD was seen between groups at week 12 (mean difference of -34 m [95% CI, -105 to 36], P = .34). For secondary outcomes, compared with the sham group, the oxygen group had a significantly higher Leicester Cough Questionnaire psychological domain score, indicating better cough-related quality of life (mean difference of 0.9 [95% CI, 0.2 to 1.6], P = .01), but a shorter duration of moderate-to-vigorous activities (mean difference of -135 [95% CI, -267 to -3], P = .04) at week 12. INTERPRETATION: Based on the results of this pilot study, a definitive randomized controlled trial with a longer intervention duration is warranted to clarify therapeutic impacts of ambulatory oxygen in patients with ILD. TRIAL REGISTRY: Australian New Zealand Clinical Trials Registry; No.: ACTRN12617000054314; URL: www.anzctr.org.au/.

Thoracic Society of Australia and New Zealand clinical practice guideline on adult home oxygen therapy

This Thoracic Society of Australia and New Zealand Guideline on the provision of home oxygen therapy in adults updates a previous Guideline from 2015. The Guideline is based upon a systematic review and meta-analysis of literature to September 2022 and the strength of recommendations is based on GRADE methodology. Long-term oxygen therapy (LTOT) is recommended for its mortality benefit for patients with COPD and other chronic respiratory diseases who have consistent evidence of significant hypoxaemia at rest (PaO2 ≤ 55 mm Hg or PaO2 ≤59 mm Hg in the presence of hypoxaemic sequalae) while in a stable state. Evidence does not support the use of LTOT for patients with COPD who have moderate hypoxaemia or isolated nocturnal hypoxaemia. In the absence of hypoxaemia, there is no evidence that oxygen provides greater palliation of breathlessness than air. Evidence does not support the use of supplemental oxygen therapy during pulmonary rehabilitation in those with COPD and exertional desaturation but normal resting arterial blood gases. Both positive and negative effects of LTOT have been described, including on quality of life. Education about how and when to use oxygen therapy in order to maximize its benefits, including the use of different delivery devices, expectations and limitations of therapy and information about hazards and risks associated with its use are key when embarking upon this treatment.

The use of noninvasive mechanical ventilation in COPD with severe hypercapnic acidosis.

STUDY OBJECTIVES: To compare the effect of noninvasive mechanical ventilation (NIV) in severely acidotic with mildly acidotic patients with acute hypercapnic chronic obstructive lung disease (COPD). DESIGN: Comparison of NIV in consecutively enrolled patients with acute hypercapnic COPD with mild (pH 7.25-7.35) or severe (pH<7.25) acidosis on time to normalise pH and improve PaCO(2), duration of NIV treatment, length of stay in hospital and survival. Results (meadian (IQR)): Twenty-nine patients had 36 episodes of acute hypercapnic respiratory failure: Seventeen with pH<7.25 and 19 with pH 7.25-7.34. Compared with the mildly acidotic group, the severely acidotic group took a similar length of time for pH to normalise and PaCO(2) improve (12 (6-34) vs 12 (4-28)h, respectively, P=0.42), with similar duration of NIV treatment (60 (35-96) vs 68 (36-48)h, respectively, P=0.25) and hospital length of stay (8 (7-18) vs 9 (5-17) days, respectively, P=0.61). Overall survival was 89%, with 95% in the mild and 82% in the severely acidotic groups. CONCLUSIONS: Noninvasive ventilation is effective in the treatment of patients with severe acidosis due to acute hypercapnic COPD.

Circadian Phase and Phase Angle Disorders in Primary Insomnia.

Objectives: We aimed to identify the prevalence of circadian phase and phase angle abnormalities in patients with insomnia. Methods: We conducted a cross-sectional, multicenter study at three sleep laboratories in the United States and Australia. Patients with insomnia and healthy control participants completed a sleep log for 7 days. Circadian phase was assessed from salivary dim light melatonin onset (DLMO) time during a 12-hour laboratory visit. Results: Seventy-nine patients meeting the Research Diagnostic Criteria for Primary, Psychophysiological, Paradoxical, and/or Idiopathic Childhood Insomnia (46 females, 35.5 ± 12.3 years [M ± SD]) and 21 controls (14 females, 34.4 ± 11.8 years). As compared to controls, patients with insomnia tried to initiate sleep on average at the same clock time (24:17 ± 1:17 hours vs. 24:13 ± 1:30 hours, respectively; p = .84) but had a later average DLMO times (20:56 ± 1:55 hours, 18:17-01:21 vs. 22:02 ± 2:02 hours, 17:11-04:52, respectively; p = .04). Consequently, patients with insomnia slept at an earlier circadian phase than controls (phase angle, bedtime-DLMO 2:13 hours (± 1:43) vs. 3:10 hours (± 1:08), respectively; p = .008), of whom 10% tried to sleep at or before DLMO (compared to 0 controls), and 22% tried to sleep before or within 1 hour after DLMO (compared to 6% of controls). Conclusions: A substantial proportion (10%-22%) of patients with insomnia initiate sleep at too early a circadian phase, implicating a circadian etiology for their insomnia. Outpatient circadian phase assessments should be considered to improve differential diagnoses in insomnia and to inform the development of appropriately timed circadian-based treatments.

A randomized, double-blind, crossover trial of the effect of oxygen on dyspnea in patients with advanced cancer.

Dyspnea is a common symptom in palliative care. Despite this, there is uncertainty regarding the role of oxygen to treat the symptom in patients with advanced illness. This randomized, double-blind, crossover trial examined the effect of oxygen versus air on the relief of dyspnea in patients with advanced cancer. Following the blinded administration of air and oxygen via nasal prongs, 51 patients rated dyspnea and indicated preferences for the blinded treatments. On average, patients improved symptomatically with both air and oxygen, and there were no significant differences between the treatments. The subgroup of 17 hypoxic patients overall did not demonstrate a significant difference between air and oxygen, despite having improved oxygen saturations when administered oxygen. Hypoxia was corrected in 13 of 17 patients using the treatment dose of 4 L/min of oxygen. The experience of dyspnea is a complex, multifactorial phenomenon, with oxygen tension not correlating with the subjective experience. The administration of either air or oxygen via nasal prongs on average confers improvement of the symptom.

Facilitating change and adaptation: the experiences of current and bereaved carers of patients with severe chronic obstructive pulmonary disease.

BACKGROUND: Patients with severe chronic obstructive pulmonary disease (COPD) experience substantial symptom burden, psychological and social morbidity. The experience of this illness has an impact beyond the patient. OBJECTIVE: This study seeks to understand the experiences and needs of family carers of people with severe COPD. DESIGN: Semistructured interviews were held with current and bereaved carers of people with severe COPD. Several areas of content were targeted in the interviews, including the experience of caring for someone with COPD, views of treatment and prognosis, information and communication needs, and the understanding of palliative care. Data were analyzed thematically. RESULTS: The carers' and bereaved carers' experiences and needs around COPD are best understood as a dynamic of change, recognition, and adaptation. Carers faced many changes as the patients' general condition deteriorated. These were changes in the nature of caring tasks, in their relationships, and their own expectations. Carers usually recognized change had happened and sought to adapt through new approaches, new equipment, a new stance of thinking, and in most cases, continued caring. Within this theme of change, recognition, and adaptation were a series of subthemes: (1) the impact of caring, (2) recognizing the role of the carer, and (3) the needs of the carer including their needs from palliative care services. CONCLUSION: The impact of caring borne by family carers is substantial and life changing. Health professionals may assist carers in their role through acknowledgement, facilitating recognition of the changes that have occurred (and their implications), and enabling creative adaptive responses for carers. Such assistance is likely to enhance the ability of carers to continue in this demanding role.

Neurobehavioral performance impairment in insomnia: relationships with self-reported sleep and daytime functioning.

STUDY OBJECTIVES: Despite the high prevalence of insomnia, daytime consequences of the disorder are poorly characterized. This study aimed to identify neurobehavioral impairments associated with insomnia, and to investigate relationships between these impairments and subjective ratings of sleep and daytime dysfunction. DESIGN: Cross-sectional, multicenter study. SETTING: Three sleep laboratories in the USA and Australia. PATIENTS: Seventy-six individuals who met the Research Diagnostic Criteria (RDC) for Primary Insomnia, Psychophysiological Insomnia, Paradoxical Insomnia, and/or Idiopathic Childhood Insomnia (44F, 35.8 ± 12.0 years [mean ± SD]) and 20 healthy controls (14F, 34.8 ± 12.1 years). INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Participants completed a 7-day sleep-wake diary, questionnaires assessing daytime dysfunction, and a neurobehavioral test battery every 60-180 minutes during an afternoon/evening sleep laboratory visit. Included were tasks assessing sustained and switching attention, working memory, subjective sleepiness, and effort. Switching attention and working memory were significantly worse in insomnia patients than controls, while no differences were found for simple or complex sustained attention tasks. Poorer sustained attention in the control, but not the insomnia group, was significantly associated with increased subjective sleepiness. In insomnia patients, poorer sustained attention performance was associated with reduced health-related quality of life and increased insomnia severity. CONCLUSIONS: We found that insomnia patients exhibit deficits in higher level neurobehavioral functioning, but not in basic attention. The findings indicate that neurobehavioral deficits in insomnia are due to neurobiological alterations, rather than sleepiness resulting from chronic sleep deficiency.