Exacerbations in Adults with Asthma: A Systematic Review and External Validation of Prediction Models.

BACKGROUND: Several prediction models assessing future risk of exacerbations in adult patients with asthma have been published. Applicability of these models is uncertain because their predictive performance has often not been assessed beyond the population in which they were derived. OBJECTIVE: This study aimed to identify and critically appraise prediction models for asthma exacerbations and validate them in 2 clinically distinct populations. METHODS: PubMed and EMBASE were searched to April 2017 for reports describing adult asthma populations in which multivariable models were constructed to predict exacerbations during any time frame. After critical appraisal, the models' predictive performances were assessed in a primary and a secondary care population for author-defined exacerbations and for American Thoracic Society/European Respiratory Society-defined severe exacerbations. RESULTS: We found 12 reports from which 24 prediction models were evaluated. Three predictors (previous health care utilization, symptoms, and spirometry values) were retained in most models. Assessment was hampered by suboptimal methodology and reporting, and by differences in exacerbation outcomes. Discrimination (area under the receiver-operating characteristic curve [c-statistic]) of models for author-defined exacerbations was better in the primary care population (mean, 0.71) than in the secondary care population (mean, 0.60) and similar (0.65 and 0.62, respectively) for American Thoracic Society/European Respiratory Society-defined severe exacerbations. Model calibration was generally poor, but consistent between the 2 populations. CONCLUSIONS: The preservation of 3 predictors in models derived from variable populations and the fairly consistent predictive properties of most models in 2 distinct validation populations suggest the feasibility of a generalizable model predicting severe exacerbations. Nevertheless, improvement of the models is warranted because predictive performances are below the desired level.

Identifying patients at risk for severe exacerbations of asthma: development and external validation of a multivariable prediction model.

BACKGROUND: Preventing exacerbations of asthma is a major goal in current guidelines. We aimed to develop a prediction model enabling practitioners to identify patients at risk of severe exacerbations who could potentially benefit from a change in management. METHODS: We used data from a 12-month primary care pragmatic trial; candidate predictors were identified from GINA 2014 and selected with a multivariable bootstrapping procedure. Three models were constructed, based on: (1) history, (2) history+spirometry and (3) history+spirometry+FeNO. Final models were corrected for overoptimism by shrinking the regression coefficients; predictive performance was assessed by the area under the receiver operating characteristic curve (AUROC) and Hosmer-Lemeshow test. Models were externally validated in a data set including patients with severe asthma (Unbiased BIOmarkers in PREDiction of respiratory disease outcomes). RESULTS: 80/611 (13.1%) participants experienced ≥1 severe exacerbation. Five predictors (Asthma Control Questionnaire score, current smoking, chronic sinusitis, previous hospital admission for asthma and ≥1 severe exacerbation in the previous year) were retained in the history model (AUROC 0.77 (95% CI 0.75 to 0.80); Hosmer-Lemeshow p value 0.35). Adding spirometry and FeNO subsequently improved discrimination slightly (AUROC 0.79 (95% CI 0.77 to 0.81) and 0.80 (95% CI 0.78 to 0.81), respectively). External validation yielded AUROCs of 0.69 (95% CI 0.63 to 0.75; 0.63 to 0.75 and 0.63 to 0.75) for the three models, respectively; calibration was best for the spirometry ­model. CONCLUSIONS: A simple history-based model extended with spirometry identifies patients who are prone to asthma exacerbations. The additional value of FeNO is modest. These models merit an implementation study in clinical practice to assess their utility. TRIAL REGISTRATION NUMBER: NTR 1756.

Symptom- and fraction of exhaled nitric oxide-driven strategies for asthma control: A cluster-randomized trial in primary care.

BACKGROUND: Aiming at partly controlled asthma (PCa) instead of controlled asthma (Ca) might decrease asthma medication use. Biomarkers, such as the fraction of exhaled nitric oxide (Feno), allow further tailoring of treatment. OBJECTIVE: We sought to assess the cost-effectiveness and clinical effectiveness of pursuing PCa, Ca, or Feno-driven controlled asthma (FCa). METHODS: In a nonblind, pragmatic, cluster-randomized trial in primary care, adults (18-50 years of age) with a doctor's diagnosis of asthma who were prescribed inhaled corticosteroids were allocated to one of 3 treatment strategies: (1) aiming at PCa (Asthma Control Questionnaire [ACQ] score <1.50); (2) aiming at Ca (ACQ score <0.75); and (3) aiming at FCa (ACQ score <0.75 and Feno value <25 ppb). During 12 months' follow-up, treatment was adjusted every 3 months by using an online decision support tool. Outcomes were incremental cost per quality-adjusted life year gained, asthma control (ACQ score), quality of life (Asthma Quality of Life Questionnaire score), asthma medication use, and severe exacerbation rate. RESULTS: Six hundred eleven participants were allocated to the PCa (n = 219), Ca (n = 203), or FCa (n = 189) strategies. The FCa strategy improved asthma control compared with the PCa strategy (P < .02). There were no differences in quality of life (P ≥ .36). Asthma medication use was significantly lower for the PCa and FCa strategies compared with the Ca strategy (medication costs: PCa, $452; Ca, $551; and FCa, $456; P ≤ .04). The FCa strategy had the highest probability of cost-effectiveness at a willingness to pay of $50,000/quality-adjusted life year (86%; PCa, 2%; Ca, 12%). There were no differences in severe exacerbation rate. CONCLUSION: A symptom- plus Feno-driven strategy reduces asthma medication use while sustaining asthma control and quality of life and is the preferred strategy for adult asthmatic patients in primary care.

Comparison between an online self-administered and an interviewer-administered version of the Asthma Control Questionnaire: a cross-sectional validation study.

BACKGROUND: Online self-management programmes for asthma have recently become available. International guidelines suggest that the Asthma Control Questionnaire (ACQ) can be used in these programmes. In order to assess the current level of control and guide therapy, the same cut-off values are being used as in conventional asthma management. However, results might differ between different types of administration of the ACQ. AIMS: To assess the agreement between an online self-administered version of the ACQ and an interviewer-administered version at a routine visit. METHODS: Cross-sectional data from primary care asthma patients in the Asthma Control Cost Utility Randomized Trial Evaluation (ACCURATE) trial aged 18-50 years and prescribed inhaled steroids were analysed. We selected patients who self-administered an ACQ online and subsequently had an ACQ completed by a nurse practitioner within 7 days at a trial-related control visit. ACQ scores were calculated and agreement assessed by paired t-tests, Pearson's correlation coefficient and a Bland-Altman plot. RESULTS: A total of 351 patients were eligible (68% female, mean age 40 years). The time interval between the two versions was 3.2 days. There was a significant difference of 0.14 (95% CI 0.09 to 0.20; p<0.001) between the results of the online self-administered ACQ (mean 1.04±0.04) and the interviewer-administered ACQ results (0.90±0.04). The Pearson correlation coefficient was 0.79. The limits of agreement (-0.86, 1.14) exceeded the predefined minimal clinically important difference between results (±0.5). The Bland-Altman plot therefore showed insufficient agreement. CONCLUSIONS: Assessment of asthma control by the ACQ is influenced by the type of administration. Our results suggest that better control of asthma is perceived when interacting with a caregiver than by online self-assessment.

Asthma control cost-utility randomized trial evaluation (ACCURATE): the goals of asthma treatment.

BACKGROUND: Despite the availability of effective therapies, asthma remains a source of significant morbidity and use of health care resources. The central research question of the ACCURATE trial is whether maximal doses of (combination) therapy should be used for long periods in an attempt to achieve complete control of all features of asthma. An additional question is whether patients and society value the potential incremental benefit, if any, sufficiently to concur with such a treatment approach. We assessed patient preferences and cost-effectiveness of three treatment strategies aimed at achieving different levels of clinical control:1. sufficiently controlled asthma2. strictly controlled asthma3. strictly controlled asthma based on exhaled nitric oxide as an additional disease marker DESIGN: 720 Patients with mild to moderate persistent asthma from general practices with a practice nurse, age 18-50 yr, daily treatment with inhaled corticosteroids (more then 3 months usage of inhaled corticosteroids in the previous year), will be identified via patient registries of general practices in the Leiden, Nijmegen, and Amsterdam areas in The Netherlands. The design is a 12-month cluster-randomised parallel trial with 40 general practices in each of the three arms. The patients will visit the general practice at baseline, 3, 6, 9, and 12 months. At each planned and unplanned visit to the general practice treatment will be adjusted with support of an internet-based asthma monitoring system supervised by a central coordinating specialist nurse. Patient preferences and utilities will be assessed by questionnaire and interview. Data on asthma control, treatment step, adherence to treatment, utilities and costs will be obtained every 3 months and at each unplanned visit. Differences in societal costs (medication, other (health) care and productivity) will be compared to differences in the number of limited activity days and in quality adjusted life years (Dutch EQ5D, SF6D, e-TTO, VAS). This is the first study to assess patient preferences and cost-effectiveness of asthma treatment strategies driven by different target levels of asthma control. TRIAL REGISTRATION: Netherlands Trial Register (NTR): NTR1756.

Simple decompression or anterior subcutaneous transposition for ulnar neuropathy at the elbow: a cost-minimization analysis--Part 2.

OBJECTIVE: A randomized controlled trial was reported recently, in which simple decompression and anterior subcutaneous transposition were compared for treatment of ulnaropathy at the elbow. Clinically, both surgical options seem to be equally effective. The objective of this study is to compare the costs, from a societal standpoint, of simple decompression versus anterior subcutaneous transposition in Euros. METHODS: Published and unpublished data from a randomized controlled trial that compared simple decompression and anterior subcutaneous transposition were used. The investigators tabulated the actual costs incurred for professional fees, use of the operating room, duration of sick leave, reintervention, and treatment of complications directly related to the surgical treatment. RESULTS: The total costs per group and per patient were statistically significantly less for those treated with simple decompression. The total median costs per patient were 1124 Euros for simple decompression and 2730 Euros for anterior subcutaneous transposition. The main difference was in the costs related to sick leave, which is significantly shorter for simple decompression. There also was a statistically significant difference in operation time in favor of simple decompression. A remarkable finding was that paid workers in both treatment groups returned to work much later than unpaid workers. CONCLUSION: Although clinically equally effective, simple decompression was associated with lower cost than anterior subcutaneous transposition for the treatment of ulnar neuropathy at the elbow. Compared with anterior subcutaneous transposition, we recommend simple decompression for the treatment of idiopathic ulnar neuropathy at the elbow.