Validation of a guideline-based composite outcome assessment tool for asthma control

Multivariate time series approaches to extract predictive asthma biomarkers from prospectively patient-collected diary data: a systematic review

OBJECTIVES

Longitudinal data are common in asthma studies, to assess asthma progression in patients and identify predictors of future outcomes, including asthma exacerbations and asthma control. Different methods can quantify temporal behaviour in prospective patient-collected diary variables to obtain predictive biomarkers of asthma outcomes. The aims of this systematic review were to evaluate methods for extracting biomarkers from longitudinally collected diary data in asthma and investigate associations between them and patient-reported outcomes (PROs) of patients with asthma.

DESIGN

Systematic review and narrative synthesis.

DATA SOURCES

MEDLINE, EMBASE, CINAHL and the Cochrane Library were searched for studies published between January 2000 and July 2023.

ELIGIBILITY CRITERIA

Included studies generated biomarkers from prospective patient-collected peak expiratory flow, symptom scores, reliever use and nocturnal awakenings, and evaluated their associations with asthma PROs, namely asthma exacerbations, asthma control, asthma-related quality of life and asthma severity.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers used standardised methods to screen and extract data from included studies. Study quality and risk of bias were assessed using the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) and the Prediction model Risk Of Bias ASessment Tool (PROBAST), respectively.

RESULTS

24 full-text articles met the inclusion criteria and were included in the review. Generally, higher levels of variability in the diary variables were associated with poorer outcomes, especially increased asthma exacerbation risk, and poor asthma control. There was increasing interest in non-parametric methods to quantify complex behaviour of diary variables (6/24). TRIPOD and PROBAST highlighted a lack of consistent reporting of model performance measures and potential for model bias.

CONCLUSION

Prospectively patient-collected diary variables aid in generating asthma assessment tools, including surrogate endpoints, for clinical trials and predictive biomarkers of adverse outcomes, warranting remote monitoring. Studies consistently lacked robust reporting of model performance. Future research should use diary variable-derived biomarkers.

Gradation of Clinical Holistic Response as New Composite Outcome to Evaluate Success in Spinal Cord Stimulation Studies for Pain

INTRODUCTION

The most prominent outcome measurement in the field of neuromodulation is pain relief. Nevertheless, the number of studies that rely on composite outcomes has increased. The aims of this study are twofold: (1) to evaluate which measures are important to include in a composite outcome and (2) to develop this new composite outcome to evaluate the degree of being a clinical holistic responder with a corresponding minimal clinical important difference (MCID).

MATERIALS AND METHODS

Data from patients with persistent spinal pain syndrome type 2 treated with High-Dose Spinal Cord Stimulation (HD-SCS) were used. Pain intensity for low back and leg pain, disability, health-related quality of life, medication use, and patient satisfaction were measured at baseline and after 12 months of HD-SCS. Exploratory and Confirmatory Factor Analyses were used to evaluate which measures should be included in the composite outcome. Anchor-based and distribution-based methods were applied to determine the MCID of the newly developed outcome measurement.

RESULTS

A three-factor model was the most appropriate for this data set, in which leg pain intensity, EQ5D VAS, and disability had the largest loading on these factors. A clinical holistic outcome was created with a total score ranging from 0 (=better [no pain, no disability, and perfect health status]) to 300 (=worse [maximal pain, maximal disability, and worst health status]). The MCID value based on an absolute change score from baseline up to 12 months of HD-SCS was 87.97. When calculating with percentage changes, a MCID value of 48.4% was revealed.

CONCLUSIONS

This new composite outcome evaluating the degree of deviation from being a holistic responder is a step toward a meaningful, overall outcome assessment for patients who are treated with SCS. Further studies to evaluate the psychometric properties and the generalizability toward other patient populations still need to be performed.

[Improving the control of asthma]

Asthma control is the cornerstone of monitoring for patients with this disease. Monitoring limited to questions of the type "how is your asthma?" underestimates the real effects of the disease. Measuring control requires assessing several criteria, which differ by the kinetics of their course during treatment. Basing monitoring on only a single criterion risks overestimating control, stepping down treatment too early, and losing control of the disease. In the case of inadequate control, uncontrolled comorbid conditions and aggravating factors or poor treatment adhesion must be sought before determining that the treatment itself is insufficient. After stepping up treatment, the chances of obtaining adequate control increase progressively with time, for at least a year. When the physician and patient jointly determine that the current treatment is the maximum acceptable, waiting may be a solution. Similarly, in seeking the minimal efficacious treatment, treatment must not be stepped down too rapidly. Once control is obtained, continuation of the treatment maintains long-term control for most patients.

Comparison of the clinical efficacy and safety of salmeterol/fluticasone propionate versus current care in the management of persistent asthma in Korea

OBJECTIVES

In the Asia-Pacific region there is a general preference for prescribing oral over inhaled medications for the treatment of asthma. This study compared inhaled salmeterol/fluticasone propionate therapy (SFC) with physician-determined current care (CC) in the management of persistent asthma in Korea.

METHODS

Adult patients with a documented history of reversibility in FEV(1) (>or= 12%) or PEF (>or= 15%), were randomised in a 2:1 ratio to unblinded treatment with SFC (50/250 microg bd or 50/500 microg bd) via Diskus (N = 284) or CC (N = 140) for 52 weeks. Morning peak expiratory flow (PEF) (primary endpoint), exacerbations, asthma symptoms and patient-reported outcome measures were recorded.

TRIAL REGISTRATION

GSK study number:100614.

RESULTS

At baseline, mean morning PEF in the SFC and CC group was 374 and 401 L/min respectively. The adjusted mean morning PEF at 52 weeks was 423 +/- 3 and 396 +/- 4 L/min for SFC and CC respectively (treatment difference of 27 +/- 5 in favour of SFC; 95% CI 17, 37; p < 0.0001). The mean rate of exacerbations over 52 weeks was significantly lower in the SFC group (SFC/CC odds ratio 0.57; 95% CI 0.44, 0.74; p < 0.0001). Treatment with SFC also resulted in a significantly greater improvement in asthma symptoms, in the number of patients assessed to have well controlled asthma (Asthma Control Test score >or= 20), and in a clinically significant improvement in overall Quality of Life. The incidence of adverse events was low and similar between the two groups and events were of the type expected in this population.

CONCLUSIONS

The results of this open-label, randomised study showed that SFC provided greater asthma control than CC in the management of persistent asthma.

Stability of asthma control with regular treatment: an analysis of the Gaining Optimal Asthma controL (GOAL) study

BACKGROUND

Uncontrolled asthma is characterized by variability. Current asthma guidelines recommend focussing on the achievement and maintenance of control but few studies have examined in detail, using composite measures of control, the stability and potential duration of control once achieved. In this post-hoc analysis of the results of the Gaining Optimal Asthma controL (GOAL) study, we examine the association between the level of asthma control achieved during the step-up phase of the study and the stability of control experienced during the maintenance phase.

METHODS

GOAL was a 1-year, randomized, stratified, double-blind study of 3421 patients with uncontrolled asthma, which compared salmeterol/fluticasone propionate combination with fluticasone propionate in achieving two composite, guideline-based measures of control: totally controlled and well-controlled asthma. We analysed the proportion and duration of time spent in control, the effect of treatment on asthma stability, and the impact of asthma control stability on unscheduled use of healthcare resources.

RESULTS

In patients achieving well-controlled or totally controlled asthma, at least well-controlled asthma was maintained for a median of almost 3 and 6 months, and for more than 85% and 95% of weeks of follow-up, respectively. A high level of stability was confirmed in a Markov analysis investigating transitional probability of change in control status. Variability in control was associated with increased probability of an unscheduled healthcare resource use (odds ratio: 1.06, P < 0.001).

CONCLUSIONS

Most patients achieving guideline-defined control can maintain at least a similar level of control with regular, stable dosing, with little likelihood of losing control.