Data quality and auditing within the Netherlands Heart Registration: using the PCI registry as an example.

AIM: The aim of this article is to present the method and results of the data quality control system and audit within the Netherlands Heart Registration (NHR) using data of patients treated with percutaneous coronary intervention (PCI) in the Netherlands as an example. METHODS: The NHR is a Dutch nationwide registry of all cardiac interventions, comprising data from all 71 hospitals, of which 30 are cardiac intervention or heart centres. Each year, within the NHR, data validation and verification is performed by standard quality controls and monitoring visits (audits). For the audit in 2019, a sample of 50-100 medical records of patients treated with PCI in 2016 and 2017 were reviewed in each hospital by an independent auditor. The data received by the NHR were compared with the information in the hospitals' medical records. In total 12 patient characteristics, 5 intervention variables and 3 outcome variables were screened. The value of a variable was considered discrepant if more than 10% of the medical records reviewed regarding this variable were not consistent with the reported data received by the NHR. RESULTS: For all variables together, the consistency was high, 97.6%. All variables, except multivessel disease (9.3% discrepancy in the 2622 medical records reviewed), had an accuracy above 95%. CONCLUSION: The results of the audit of the PCI medical records show that the overall quality of the data is high. For variables such as multivessel disease it is important to improve knowledge of the definitions and to train all those involved in the registration process.

The Mental Health Quality of Life Questionnaire (MHQoL): development and first psychometric evaluation of a new measure to assess quality of life in people with mental health problems.

PURPOSE: The purpose of this study was to develop and psychometrically evaluate a new quality of life measure for use in people with mental health problems-the Mental Health Quality of Life questionnaire (MHQoL). METHODS: The MHQoL dimensions were based on prior research by Connell and colleagues, highlighting the seven most important quality of life dimensions in the context of mental health. Items were generated following a systematic review we performed and through inviting expert opinion. A focus group and an online qualitative study (N = 120) were carried out to assess the face and content validity of the MHQoL. The MHQoL was further tested for its internal consistency, convergent validity, known-group validity and test-retest reliability among mental healthcare service users (N = 479) and members of the general population (N = 110). RESULTS: The MHQoL consists of a descriptive system (MHQoL-7D), including s items covering seven dimensions (self-image, independence, mood, relationships, daily activities, physical health, future) and a visual analogue scale of general psychological well-being (MHQoL-VAS). Internal consistency was high (Cronbach's ∝ = 0.85) and correlations between MHQoL-7D scores and related measures (EQ-5D-5L, MANSA, ICECAP-A, and BSI) supported convergent validity. The intraclass correlation coefficient of the MHQoL-7D sum score for test-retest reliability was 0.85. Known-group validity was supported by the ability to detect significant differences in MHQoL-7D levels between service users and the general population, and between groups with different levels of psychological distress. CONCLUSION: The MHQoL demonstrated favourable psychometric properties and showed promise as a simple and effective measure to assess quality of life in people with mental health problems.

A randomised comparison of the effect of haemodynamic monitoring with CardioMEMS in addition to standard care on quality of life and hospitalisations in patients with chronic heart failure : Design and rationale of the MONITOR HF multicentre randomised clinical trial.

BACKGROUND: Assessing haemodynamic congestion based on filling pressures instead of clinical congestion can be a way to further improve quality of life (QoL) and clinical outcome by intervening before symptoms or weight gain occur in heart failure (HF) patients. The clinical efficacy of remote monitoring of pulmonary artery (PA) pressures (CardioMEMS; Abbott Inc., Atlanta, GA, USA) has been demonstrated in the USA. Currently, the PA sensor is not reimbursed in the European Union as its benefit when applied in addition to standard HF care is unknown in Western European countries, including the Netherlands. AIMS: To demonstrate the efficacy and cost-effectiveness of haemodynamic PA monitoring in addition to contemporary standard HF care in a high-quality Western European health care system. METHODS: The current study is a prospective, multi-centre, randomised clinical trial in 340 patients with chronic HF (New York Heart Association functional class III) randomised to HF care including remote monitoring with the CardioMEMS PA sensor or standard HF care alone. Eligible patients have at least one hospitalisation for HF in 12 months before enrolment and will be randomised in a 1:1 ratio. Minimum follow-up will be 1 year. The primary endpoint is the change in QoL as measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ). Secondary endpoints are the number of HF hospital admissions and changes in health status assessed by EQ-5D-5L questionnaire including health care utilisation and formal cost-effectiveness analysis. CONCLUSION: The MONITOR HF trial will evaluate the efficacy and cost-effectiveness of haemodynamic monitoring by CardioMEMS in addition to standard HF care in patients with chronic HF. Clinical Trial Registration number NTR7672.

Health-related quality of life and its determinants in patients with metastatic renal cell carcinoma.

PURPOSE: Based on improvements of progression-free survival (PFS), new agents for metastatic renal cell carcinoma (mRCC) have been approved. It is assumed that one of the benefits is a delay in health-related quality of life (HRQoL) deterioration as a result of a delay in progression of disease. However, little data are available supporting this relationship. This study aims to provide insight into the most important determinants of HRQoL (including progression of disease) of patients with mRCC. METHODS: A patient registry (PERCEPTION) was created to evaluate treatment of patients with (m)RCC in the Netherlands. HRQoL was measured, using the EORTC QLQ-C30 and EQ-5D-5L, every 3 months in the first year of participation in the study, and every 6 months in the second year. Participation started as soon as possible following a diagnosis of (m)RCC. Random effects models were used to study associations between HRQoL and patient and disease characteristics, symptoms and treatment. RESULTS: Eighty-seven patients with mRCC completed 304 questionnaires. The average EORTC QLQ-C30 global health status was 69 (SD, 19) before progression and 61 (SD, 22) after progression of disease. Similarly, the average EQ-5D utility was 0.75 (SD, 0.19) before progression and 0.66 (SD, 0.30) after progression of disease. The presence of fatigue, pain, dyspnoea, and the application of radiotherapy were associated with significantly lower EQ-5D utilities. CONCLUSIONS: Key drivers for reduced HRQoL in mRCC are disease symptoms. Since symptoms increase with progression of disease, targeted therapies that increase PFS are expected to postpone reductions in HRQoL in mRCC.

Genetic and phenotypically flexible components of seasonal variation in immune function.

Animals cope with seasonal variation in environmental factors by adjustments of physiology and life history. When seasonal variation is partly predictable, such adjustments can be based on a genetic component or be phenotypically flexible. Animals have to allocate limited resources over different demands, including immune function. Accordingly, immune traits could change seasonally, and such changes could have a genetic component that differs between environments. We tested this hypothesis in genotypically distinct groups of a widespread songbird, the stonechat (Saxicola torquata). We compared variation in immunity during 1 year in long-distance migrants, short-distance migrants, tropical residents and hybrids in a common garden environment. Additionally, we investigated phenotypically flexible responses to temperature by applying different temperature regimes to one group. We assessed constitutive immunity by measuring hemagglutination, hemolysis, haptoglobin and bactericidal ability against Escherichia coli and Staphylococcus aureus. Genotypic groups differed in patterns of variation of all measured immune indices except haptoglobin. Hybrids differed from, but were rarely intermediate to, parental subspecies. Temperature treatment only influenced patterns of hemolysis and bactericidal ability against E. coli. We conclude that seasonal variation in constitutive immunity has a genetic component, that heredity does not follow simple Mendelian rules, and that some immune measures are relatively rigid while others are more flexible. Furthermore, our results support the idea that seasonal variability in constitutive immunity is associated with variability in environment and annual-cycle demands. This study stresses the importance of considering seasonal variation in immune function in relation to the ecology and life history of the organism of interest.

Heart disease in the Netherlands: a quantitative update.

In this review we discuss cardiovascular mortality, incidence and prevalence of heart disease, and cardiac interventions and surgery in the Netherlands. We combined most recently available data from various Dutch cardiovascular registries, Dutch Hospital Data (LMR), Statistics Netherlands (CBS), and population-based cohort studies, to provide a broad quantitative update. The absolute number of people dying from cardiovascular diseases is declining and cardiovascular conditions are no longer the leading cause of death in the Netherlands. However, a substantial burden of morbidity persists with 400,000 hospitalisations for cardiovascular disease involving over 80,000 cardiac interventions annually. In the Netherlands alone, an estimated 730,000 persons are currently diagnosed with coronary heart disease, 120,000 with heart failure, and 260,000 with atrial fibrillation. These numbers emphasise the continuous need for dedicated research on prevention, diagnosis, and treatment of heart disease in our country.

Cardiologist and cardiac surgeon view on decision-making in prosthetic aortic valve selection: does profession matter?

AIMS: Assess and compare among Dutch cardiothoracic surgeons and cardiologists: opinion on (1) patient involvement, (2) conveying risk in aortic valve selection, and (3) aortic valve preferences. METHODS AND RESULTS: A survey among 117 cardiothoracic surgeons and cardiologists was conducted. Group responses were compared using the Mann-Whitney U test. Most respondents agreed that patients should be involved in decision-making, with surgeons leaning more toward patient involvement (always: 83 % versus 50 % respectively; p < 0.01) than cardiologists. Most respondents found that ideally doctors and patients should decide together, with cardiologists leaning more toward taking the lead compared with surgeons (p < 0.01). Major risks of the therapeutic options were usually discussed with patients, and less common complications to a lesser extent. A wide variation in valve preference was noted with cardiologists leaning more toward mechanical prostheses, while surgeons more often preferred bioprostheses (p < 0.05). CONCLUSION: Patient involvement and conveying risk in aortic valve selection is considered important by cardiologists and cardiothoracic surgeons. The medical profession influences attitude with regard to aortic valve selection and patient involvement, and preference for a valve substitute. The variation in valve preference suggests that in most patients both valve types are suitable and aortic valve selection may benefit from evidence-based informed shared decision-making.

An unanticipated copy number variant of chromosome 15 disrupting SMAD3 reveals a three-generation family at serious risk for aortic dissection.

Several genes involved in the familial appearance of thoracic aortic aneurysms and dissections (FTAAD) have been characterized recently, one of which is SMAD3. Mutations of SMAD3 cause a new syndromic form of aortic aneurysms and dissections associated with skeletal abnormalities. We discovered a small interstitial deletion of chromosome 15, leading to disruption of SMAD3, in a boy with mild mental retardation, behavioral problems and revealed features of the aneurysms-osteoarthritis syndrome (AOS). Several family members carried the same deletion and showed features including aortic aneurysms and a dissection. This finding demonstrates that haploinsufficiency of SMAD3 leads to development of both thoracic aortic aneurysms and dissections, and the skeletal abnormalities that form part of the aneurysms-osteoarthritis syndrome. Interestingly, the identification of this familial deletion is an example of an unanticipated result of a genomic microarray and led to the discovery of important but unrelated serious aortic disease in the proband and family members.

Fewer invited talks by women in evolutionary biology symposia.

Lower visibility of female scientists, compared to male scientists, is a potential reason for the under-representation of women among senior academic ranks. Visibility in the scientific community stems partly from presenting research as an invited speaker at organized meetings. We analysed the sex ratio of presenters at the European Society for Evolutionary Biology (ESEB) Congress 2011, where all abstract submissions were accepted for presentation. Women were under-represented among invited speakers at symposia (15% women) compared to all presenters (46%), regular oral presenters (41%) and plenary speakers (25%). At the ESEB congresses in 2001-2011, 9-23% of invited speakers were women. This under-representation of women is partly attributable to a larger proportion of women, than men, declining invitations: in 2011, 50% of women declined an invitation to speak compared to 26% of men. We expect invited speakers to be scientists from top ranked institutions or authors of recent papers in high-impact journals. Considering all invited speakers (including declined invitations), 23% were women. This was lower than the baseline sex ratios of early-mid career stage scientists, but was similar to senior scientists and authors that have published in high-impact journals. High-quality science by women therefore has low exposure at international meetings, which will constrain Evolutionary Biology from reaching its full potential. We wish to highlight the wider implications of turning down invitations to speak, and encourage conference organizers to implement steps to increase acceptance rates of invited talks.

Upper thoracic epidural anaesthesia: effects of age on neural blockade and cardiovascular parameters.

BACKGROUND: Segmental dose reduction with increasing age after thoracic epidural anaesthesia (TEA) has been documented. We hypothesised that after a fixed loading dose of ropivacaine at the T3-T4 level, increasing age would result in more extended analgesic spread. In addition, other aspects of neural blockade and haemodynamic changes were studied. METHODS: Thirty-five lung surgery patients were included in three age groups. Thirty-one patients received an epidural catheter at the T3-T4 interspace followed by an injection of 8-ml ropivacaine 0.75%. Analgesia was assessed with pinprick and temperature discrimination. Motor block was tested using the Bromage and epidural scoring scale for arm movements score. An arterial line was inserted for invasive measurement of blood pressure, cardiac index (CI) and stroke volume (SV). RESULTS: There was no influence of age on quality of TEA except for the caudal border of analgesia being somewhat lower in the middle and older age group compared with the young age group. Heart rate (6.0 ± 5.9, P < 0.001), mean arterial pressure (16.1 ± 15.6, P < 0.001), CI (0.55 ± 0.49, P < 0.001) and SV (9.6 ± 14.6, P = 0.001) decreased after TEA for the total group. Maximal reduction in heart rate after TEA was more extensive in the young age group compared with the other age groups. There was no effect of age on other cardiovascular parameters. CONCLUSION: We were unable to demonstrate an effect of age on the maximal number of spinal segments blocked after TEA; however, the caudad spread of analgesia increased with advancing age. In addition, reduction of heart rate was greater in the youngest group.

Do immunological, endocrine and metabolic traits fall on a single Pace-of-Life axis? Covariation and constraints among physiological systems.

Variation in demographic and physiological attributes of life history is thought to fall on one single axis, a phenomenon termed the Pace-of-Life. A slow Pace-of-Life is characterized by low annual reproduction, long life span and low metabolic rate, a fast Pace-of-Life by the opposite characteristics. The existence of a single axis has been attributed to constraints among physiological mechanisms that are thought to restrict evolutionary potential. In that case, physiological traits should covary in the same fashion at the levels of individual organisms and species. We examined covariation at the levels of individual and subspecies in three physiological systems (metabolic, endocrine and immune) using four stonechat subspecies with distinct life-history strategies in a common-garden set-up. We measured basal metabolic rate, corticosterone as endocrine measure and six measures of constitutive immunity. Metabolic rate covaried with two indices of immunity at the individual level, and with corticosterone concentrations and one index of immunity at the subspecies level, but not with other measures. The different patterns of covariation among individuals and among subspecies demonstrate that links among physiological traits are loose and suggest that these traits can evolve independent of each other.

Independence among physiological traits suggests flexibility in the face of ecological demands on phenotypes.

Phenotypic flexibility allows animals to adjust their physiology to diverse environmental conditions encountered over the year. Examining how these varying traits covary gives insights into potential constraints or freedoms that may shape evolutionary trajectories. In this study, we examined relationships among haematocrit, baseline corticosterone concentration, constitutive immune function and basal metabolic rate in red knot Calidris canutus islandica individuals subjected to experimentally manipulated temperature treatments over an entire annual cycle. If covariation among traits is constrained, we predict consistent covariation within and among individuals. We further predict consistent correlations between physiological and metabolic traits if constraints underlie species-level patterns found along the slow-fast pace-of-life continuum. We found no consistent correlations among haematocrit, baseline corticosterone concentration, immune function and basal metabolic rate either within or among individuals. This provides no evidence for constraints limiting relationships among these measures of the cardiovascular, endocrine, immune and metabolic systems in individual red knots. Rather, our data suggest that knots are free to adjust individual parts of their physiology independently. This makes good sense if one places the animal within its ecological context where different aspects of the environment might put different pressures on different aspects of physiology.

Annual cycles of metabolic rate are genetically determined but can be shifted by phenotypic flexibility.

Birds have adjusted their life history and physiological traits to the characteristics of the seasonally changing environments they inhabit. Annual cycles in physiology can result from phenotypic flexibility or from variation in its genetic basis. A key physiological trait that shows seasonal variation is basal metabolic rate (BMR). We studied genetic and phenotypic variation in the annual cycles of body mass, BMR and mass-specific BMR in three stonechat subspecies (Saxicola torquata) originating from environments that differ in seasonality, and in two hybrid lines. Birds were kept in a common garden set-up, under annually variable day length and at constant temperature. We also studied whether stonechats use the proximate environmental factor temperature as a cue for changes in metabolic rate, by keeping birds at two different temperature regimes. We found that the different subspecies kept in a common environment had different annual cycles of body mass, BMR (variance: Kazakh 4.12, European 1.31, Kenyans 1.25) and mass-specific BMR (variance: Kazakh 0.042, European 0.003, Kenyans 0.013). Annual variation in metabolic measures of hybrids was intermediate or similar to that of parental species. Temperature treatment did not affect the shape of the annual cycles of metabolic rate, but metabolic rate was higher in birds kept under the variable temperature regime. The distinct annual cycles in body mass and metabolic rate in stonechat subspecies kept in a common environment indicate different genetic backgrounds rather than merely a phenotypically flexible response to proximate environmental cues. Phenotypic effects of temperature are superimposed on this genetically orchestrated annual cycle.

Quality of life among people living with HIV in England and the Netherlands: a population-based study.

BACKGROUND: HIV is now considered a chronic condition, and people living with HIV, when treated, have a similar life expectancy as compared to the general population. Consequently, improving and ensuring a good health-related quality of life (HrQoL) among people living with HIV (people living with HIV) is increasingly important and has risen on the global agenda in recent years. A 'fourth 90' as 90% of people with viral load suppression have a good HrQoL should therefore be adopted alongside the other 90-90-90 targets. This study aims to report the progress on HrQoL as the 'fourth 90' and compare against the general population in the Netherlands and England. METHODS: In the Netherlands, individuals attending the HIV outpatient clinic of a tertiary hospital were asked to complete the EQ-5D-5L from June 2016 until December 2018. In England, individuals attending one of 73 HIV outpatient clinics were randomly sampled to complete the Positive Voices survey, which included the EQ-5D-5L, from January to September 2017. HrQoL scores were combined with demographic data and compared to general population data. FINDINGS: The EQ-5D-5L was filled-out by 895 people living with HIV in the NL and 4,137 in England. HrQoLutility was 0·85 among Dutch and 0·83 among English people living with HIV. This equated to 98% and 94% of the general population HrQoLutility in the Netherlands and England, respectively. Of the EQ-5D domains, anxiety/depression was mostly affected, with one-third in Dutch (35%) and almost half (47%) of English people living with HIV reporting symptoms. This was higher compared to their respective general populations (21% NL and 31% England). INTERPRETATION: Overall, HrQoLutility for people living with HIV was high in both countries and highly comparable to the general populations Nevertheless, there should be an increased focus on anxiety and depression in the people living with HIV population The EQ-5D-5L proved an easy HrQoL measurement tool and identified areas for improvement by social and behavioural interventions. FUNDING: The study received funding (unrestricted grants) from: Gilead sciences, ViiV Healthcare, MSD, and Jansen pharmaceuticals.

[Pharmaceutical pricing; what is reasonable?] / Prijsbepaling van medicijnen.

The ultimate aim of investigations into the costs of research and development (R&D) is to inform societal discussions on drug affordability. The premise is that knowing R&D costs will help when setting 'reasonable' drug prices. While high R&D costs may explain why prices are high, these costs need not justify paying those prices when health gains are limited. Value-based pricing models that explicitly take health gains into account also have limitations, most notably that they ignore R&D costs and consider prices to be 'reasonable' simply because other high costs of care can be avoided. Both cost-based and value-based pricing models are necessary to determine whether prices are reasonable; however, redesigning the drug innovation ecosystem could bring a more relevant contribution to reasonable drug prices than evaluation of the reasonableness of the price.

[Pulmonary sequestrum--not infiltrate--in a 45-year-old woman]. / Geen pulmonaal infiltraat, maar een longsekwester bij een 45-jarige vrouw.

A 45-year-old woman presented at the emergency room with acute dyspnoea and slight fever, without coughing. The chest radiography showed a consolidation in the lower left lobe. The CT scan revealed a consolidation in the posterior-basal segment of the lower left lobe without an air bronchogram but with various densities. Based on these findings, the possibility of pulmonary sequestration was considered. A CT scan showed an arterial branch arising from the aorta that supplied the consolidation, confirming pulmonary sequestration. The patient underwent resection of the intralobar sequestrum, after which she recovered and was asymptomatic. Pulmonary sequestration should be considered in any patient with pneumonia or recurrent pneumonia in the lower lobes of the lung, especially in the absence of an air bronchogram or signs of endobronchial obstruction. The treatment ofchoice is surgical resection.

Patient and general public preferences for health states: A call to reconsider current guidelines.

In economic evaluations of health care interventions, benefits are often expressed in terms of Quality-Adjusted Life-Years (QALYs). The QALY comprises length and quality of life into one measure which allows cross-disease comparability. The quality adjustment of the QALY is based on preferences for health states. An important normative choice is the question whose preferences for states of health we wish to capture. The answer to this question is directly related to the normative question regarding the appropriate maximand in health care decisions. Currently, preferences are commonly derived from the general public, rather than from actual patients. This choice, which can have large consequences on final outcomes of economic evaluations, has always been a topic of debate. This paper clarifies and furthers the discussion regarding the appropriate source of preferences for health state valuations, acknowledges the plurality of different perspectives, and argues that health economic guidelines could require analysis of benefit in terms of QALYs based on both patient and general public preferences.

A phase I study for intravenous autologous mesenchymal stromal cell administration to patients with severe emphysema.

BACKGROUND: Mesenchymal stromal cells (MSCs) may reduce inflammation and promote tissue repair in pulmonary emphysema. AIM: To study the safety and feasibility of bone marrow-derived autologous (BM-) MSC intravenous administration to patients with severe emphysema. DESIGN: A phase I, prospective open-label study registered at ClinicalTrials.gov as NCT01306513 Eligible patients had lung volume reduction surgery (LVRS) on two separate occasions. During the first LVRS bone marrow was collected, from which MSCs were isolated and expanded ex vivo After 8 weeks, patients received two autologous MSC infusions 1 week apart, followed by the second LVRS procedure at 3 weeks after the second BM-MSC infusion. METHODS: Up to 3 weeks after the last MSC infusion adverse events were recorded. Using immunohistochemistry and qPCR for analysis of cell and proliferation markers, emphysematous lung tissue obtained during the first surgery was compared with lung tissue obtained after the second surgical session to assess BM-MSC effects. RESULTS: From 10 included patients three were excluded: two did not receive MSCs due to insufficient MSC culture expansion, and one had no second surgery. No adverse events related to MSC infusions occurred and lung tissue showed no fibrotic responses. After LVRS and MSC infusions alveolar septa showed a 3-fold increased expression of the endothelial marker CD31 (P = 0.016). CONCLUSIONS: Autologous MSC treatment in severe emphysema is feasible and safe. The increase in CD31 expression after LVRS and MSC treatment suggests responsiveness of microvascular endothelial cells in the most severely affected parts of the lung.

Double-blind, randomized controlled trial on the effect of leukocyte-depleted erythrocyte transfusions in cardiac valve surgery.

BACKGROUND: Leukocytes in allogeneic blood transfusions are believed to be the cause of immunomodulatory events. A few trials on leukocyte removal from transfusions in cardiac surgery have been conducted, and they showed inconclusive results. We found in a previous study a decrease in mortality rates and number of infections in a subgroup of more heavily transfused patients. METHODS AND RESULTS: Patients (n=496) undergoing valve surgery (with or without CABG) were randomly assigned in a double-blind fashion to receive standard buffy coat-depleted (PC) or prestorage, by filtration, leukocyte-depleted erythrocytes (LD). The primary end point was mortality at 90 days, and secondary end points were in-hospital mortality, multiple organ dysfunction syndrome, infections, intensive care unit stay, and hospital stay. The difference in mortality at 90 days was not significant (PC 12.7% versus LD 8.4%; odds ratio [OR], 1.52; 95% confidence interval [CI], 0.84 to 2.73). The in-hospital mortality rate was almost twice as high in the PC group (10.1% versus 5.5% in the LD group; OR, 1.99; 95% CI, 0.99 to 4.00). The incidence of multiple organ dysfunction syndrome in both groups was similar, although more patients with multiple organ dysfunction syndrome died in the PC group. LD was associated with a significantly reduced infection rate (PC 31.6% versus LD 21.6%; OR, 1.64; 95% CI, 1.08 to 2.49). In both groups, intensive care unit stay and hospital stay were similar, and postoperative complications increased with the number of transfused units. CONCLUSIONS: Mortality at 90 days was not significantly different; however, a beneficial effect of LD in valve surgery was found for the secondary end points of in-hospital mortality and infections.

Long-term effect of bilateral plication of the diaphragm.

STUDY OBJECTIVES: To assess the feasibility and clinical outcome of bilateral plication of the diaphragm in patients with bilateral diaphragmatic paralysis (BDP) caused by neuralgic amyotrophy (NA), a mononeuritis of the phrenic nerves. DESIGN: Prospective, case-control study over a 1-year period. SETTING: A university hospital in The Netherlands. PATIENTS: Six patients who presented with BDP caused by NA. METHODS: The diagnosis of BDP was based on the absence of muscle response after cervical magnetic stimulation of both phrenic nerves. Three patients did not undergo surgery but were observed for a period of 2 years, and the other three patients underwent a limited lateral thoracotomy at the eighth intercostal space. Plication was performed by U-stitches until the diaphragm was as tight as possible. Vital capacity (VC) and arterial blood gas was measured during follow-up. RESULTS: One month postoperatively, mean VC measured in the supine position was significantly improved by 17%, and this effect was sustained for 12 months. Arterial PO(2) increased by 45%. VC and blood gas levels did not improve in the three patients that were only observed during the 2-year period. All three surgical patients could sleep in the supine position after the operation. CONCLUSION: Bilateral plication of the diaphragm for NA-induced paralysis results in improvement of ventilation and blood gas exchange, allowing patients to sleep in the supine position without dyspnea.