Predicting changes in clinical status of young asthmatics: clinical scores or objective parameters?

Composite predictive models for asthma exacerbations or asthma deterioration in pediatric asthmatic patients: A systematic review of the literature

A variety of factors have shown to be useful in predicting which children are at high risk for future asthma exacerbations, some of them combined into composite predictive models. The objective of the present review was to systematically identify all the available published composite predictive models developed for predicting which children are at high risk for future asthma exacerbations or asthma deterioration. A systematic search of the literature was performed to identify studies in which a composite predictive model developed for predicting which children are at high risk for future asthma exacerbations or asthma deterioration was described. Methodological quality assessment was performed using accepted criteria for prediction rules and prognostic models. A total of 18 articles, describing a total of 17 composite predictive models were identified and included in the review. The number of predictors included in the models ranged from 2-149. Upon analyzing the content of the models, use of healthcare services for asthma and prescribed or dispensed asthma medications were the most frequently used items (in 8/17, 47.0% of the models). Seven (41.2%) models fulfilled all the quality criteria considered in our evaluation. The identified models may help clinicians dealing with asthmatic children to identify which children are at a higher risk for future asthma exacerbations or asthma deterioration, therefore targeting and/or reinforcing specific interventions for these children in an attempt to prevent exacerbations or deterioration of the disease.

Validity of the Childhood Asthma Control Test in diverse populations: A systematic review

PURPOSE

We examined the validity of the Childhood Asthma Control Test (C-ACT) and identified recommended thresholds for uncontrolled asthma in children from varying backgrounds.

METHODS

A systematic literature review was performed utilizing PubMed, Ovid Medline, SCOPUS, CINAHL, and conference proceedings. Studies were included if they enrolled children, had a primary outcome of asthma control, examined test validity or psychometrics, and utilized the C-ACT. Along with study design and demographic data, we extracted all outcomes and comparisons used to validate the C-ACT. We evaluated risk of bias using the COSMIN Risk of Bias tool. Our protocol was registered with PROSPERO (CRD42020211119).

RESULTS

Of 4924 records screened, 28 studies were included. Studies were conducted internationally and published between 2007 and 2018. Average number of enrolled participants was 193 (SD = 155, range = 22-671). Ten studies calculated Cronbach's α (mean [SD] = 0.78(0.05), range = 0.677-0.83). Thirteen studies recommended cut-offs for uncontrolled asthma (≤18-≤24). Nine studies found significant agreement or correlation between C-ACT and Global Initiative for Asthma guidelines/physician assessment of asthma control (correlation coefficients range = 0.219-0.65). Correlation coefficients between C-ACT and spirometry were <0.6 in five of six studies that included spirometry. Kappa values for C-ACT and various spirometry measurements ranged 0.00-0.34.

CONCLUSIONS

The C-ACT showed good internal consistency and mixed levels of agreement and correlation with various clinical asthma measures. Recommended cut-offs for asthma control varied and had no consistent relationship with nationality, race, ethnicity, or language. Few studies examined cross-cultural validity and multiple populations remain under-studied.

Development and validation of a risk score to identify children at risk of life-threatening asthma

OBJECTIVE

To develop and validate a prediction risk score for identification of children at risk of developing life-threatening asthma (LTA).

METHODS

Our study utilized existing medical records and retrospective analysis to develop and validate a risk score. The study population included children aged 2-17 years, admitted with a primary diagnosis of asthma, to Sydney Children's Hospital between 2011-2016. Children admitted in the intensive care unit with asthma at risk of LTA (cases) and those admitted into general ward (comparison group), were randomly divided into a derivation and a validation cohort. Candidate predictors from derivation cohort were selected through multivariable regression, which were used to estimate each child's risk of developing LTA in the validation cohort. Predictive performance of the risk score was evaluated by the area under the receiver operating characteristic curve (AUROC) and Hosmer-Lemeshow goodness-of-fit test.

RESULTS

The study population comprised of 1171 children; 586 in the derivation and 585 in the validation cohort. Four independent candidate variables from derivation cohort (age at admission, socioeconomic status, a family history of asthma/atopy and previous asthma hospitalizations) were retained in the predictive model (AUROC 0.759; 95% CI, 0.694-0.823), with a sensitivity of 78.5% and specificity of 46.6%.

CONCLUSIONS

Our risk algorithm based on routinely collected clinical data may be used to develop a user-friendly risk score for early identification and monitoring of children at risk of developing LTA.

[The Childhood Asthma Control Test improves the therapeutic adaptations recommended for asthmatics aged 6 to 11 years in primary practice. A Randomized comparative prospective study]

OBJECTIVES

Asthma is the leading chronic disease of the child; control and treatment remain inadequate. Our objective was to assess whether the use of the Childhood Asthma Control Test (C -ACT) in primary care had an impact on adapting therapy.

METHODS

The study was quantitative prospective and compared 2 groups of general practioners. All had the same reminders about childhood asthma management. The C-ACT was detailed to one group only. Doctors in the control group had to work as usual without C-ACT. Doctors included asthmatic children aged 6 to 11 years who were consulting for their asthma or any other reason. The primary endpoint was the adaptation of asthma treatment according to the Global Initative for Asthma (GINA). Evaluations of the control group were compared with the after consultation self-administered online C-ACT.

RESULTS

From April to October 2014, 61 physicians included 179 patients in two comparable groups. Although not significant statistically, doctors using C-ACT found 45% of uncontrolled asthma (vs. 31%). When the reason for consultation was not related to asthma, the figure was 25% (vs. 15%). Doctors using the C-ACT made twice less therapeutic adaptations not recommended by the GINA: 8% vs. 16%. 25% of evaluations of doctors in the control group were discordant with the internet C-ACT. After correction with the internet C-ACT of these imprecise initial assessments, the figure was 25%: 3 times more than in the C-ACT group (P=0.014).

CONCLUSION

The use in primary care of C-ACT should allow a better assessment of asthma control and adaptation of treatment in children.

Asthma control in children: Body plethysmography in addition to spirometry

BACKGROUND

There is a lack of agreement among measures of asthma control in children. In Central Europe, body plethysmography is additionally used for asthma monitoring. However, its value is still unclear.

OBJECTIVES

We investigated the possible additional value of body plethysmographic measures (specific resistance, residual volume-total lung capacity ratio [RV/TLC]) compared with spirometric measures forced expiratory volume in 1 second (FEV ₁ ), forced vital capacity (FVC), FEV ₁ /FVC, forced expiratory flow at 25% to 75% of forced vital capacity (FEF _25-75 ), and fraction of exhaled nitric oxide (FeNO) for assessment of asthma control.

METHODS

One hundred and forty-five asthmatic children aged 5 to 17 were included. All children performed measurements of FeNO, spirometry, and body plethymography. Asthma control was assessed by the asthma control test (c-ACT/ACT) and a doctor's assessment of asthma control.

RESULTS

Investigating single lung function parameters, FEV₁ , FEV ₁ /FVC, FEF _25-75 and RV/TLC differed between controlled and partly controlled asthma. However, we found no differences between controlled and uncontrolled asthma with regard to single lung function parameters or for any parameter if investigated in a multivariable approach. This was also true if we combined obtained parameters from spirometry (comparing pathologic vs normal spirometry). Investigating the combination of body plethysmography and doctor's assessment of asthma control a significant association was found ( P = 0.02). Furthermore, combined spirometry and body plethysmography showed a significant association with both doctor's assessed asthma control ( P = 0.009) and the c-ACT/ACT ( P = 0.04). The addition of FeNO did not improve the results.

CONCLUSIONS

The combination of body plethysmography and spirometry shows best agreement with asthma control in children compared with spirometry or body plethysmography alone. Further studies are needed to find out whether additional measurements of body plethysmography improve the outcome of children in asthma monitoring.

Development of a nomogram to estimate the quality of life in asthmatic children using the Childhood Asthma Control Test

BACKGROUND

Pediatric Asthma Quality of Life Questionnaire (PAQLQ) provides detailed information on QoL in asthmatic children, whereas Childhood Asthma Control Test (C-ACT) Questionnaire is the most validated instrument for asthma control. No study assessed the relationship between C-ACT and QoL in children by means of those instruments. The aim of this study was to determine whether a QoL estimation is possible using the C-ACT questionnaire in asthmatic children.

METHODS

Medical history, spirometry, C-ACT, and PAQLQ were assessed in 144 (60% male) outpatient asthmatic children from September 2011 to November 2014. A generalized linear model (GLM) for the prediction of PAQLQ was obtained through a stepwise procedure starting from a full model with all C-ACT items, and predictive nomograms were created.

RESULTS

Fifty-five (38%) well-controlled (WC) asthma, 37 (26%) partially controlled (PC) asthma, and 52 (36%) uncontrolled asthma (UA) patients were enrolled. Persistent asthmatics (PA) were significantly more uncontrolled (p < 0.0001). A significant reduction in FEV1 , FEV1 /FVC, and FEF25-75 (p = 0.005, p < 0.0001, and p < 0.001, respectively) was found in WC vs. UA. Through a stepwise process, a reduced model showed a positive relationship between the PAQLQ and the four items of C-ACT. The regression equations for predicted PAQLQ were ln(PAQLQ) = 1.17 + 0.05*C-ACT2 + 0.03*C-ACT3 + 0.04*C-ACT6 + 0.03*C-ACT7. Thus, a nomogram was constructed.

CONCLUSION

The designed nomogram provides a highly predictive assessment of QoL in individual patients, facilitating a more comprehensive assessment of asthmatic children in usual clinical care.

Disagreement among common measures of asthma control in children

BACKGROUND

Asthma is a worldwide problem. It cannot be prevented or cured, but it is possible, at least in principle, to control asthma with modern management. Control usually is assessed by history of symptoms, physical examination, and measurement of lung function. A practical problem is that these measures of control may not be in agreement. The aim of this study was to describe agreement among different measures of asthma control in children.

METHODS

A prospective sequential sample of children aged 4 to 11 years with atopic asthma attending a routine follow-up evaluation were studied. Patients were assessed with the following four steps: (1) fraction of exhaled nitric oxide (FENO), (2) spirometry, (3) Childhood Asthma Control Test (cACT), and (4) conventional clinical assessment by a pediatrician. The outcome for each test was coded as controlled or uncontrolled asthma. Agreement among measures was examined by cross-tabulation and κ statistics.

RESULTS

Eighty children were enrolled, and nine were excluded. Mean FENO in pediatrician-judged uncontrolled asthma was double that of controlled asthma (37 parts per billion vs 15 parts per billion, P < .005). There was disagreement among measures of control. Spirometric indices revealed some correlation, but of the unrelated comparisons, those that agreed with each other most often (69%) were clinical assessment by the pediatrician and the cACT. Worst agreement was noted for FENO and cACT (49.3%).

CONCLUSION

Overall, different measures to assess control of asthma showed a lack of agreement for all comparisons in this study.

Evaluation of the asthma control test: a reliable determinant of disease stability and a predictor of future exacerbations

BACKGROUND AND OBJECTIVE

This study assessed the asthma control test (ACT) cut-off values for asthma control according to the Global Initiative for Asthma guideline in adults and the effectiveness of ACT scores in predicting exacerbations and serial changes in ACT scores over time in relation to treatment decisions.

METHODS

Subjects completed ACT together with same-day spirometry and fractional concentration of exhaled nitric oxide (FeNO) measurement at baseline and at 3 months. Physicians, blinded to the ACT scores and FeNO values, assessed the patient's asthma control in the past month and adjusted the asthma medications according to management guidelines. Asthma exacerbations and urgent health-care utilization (HCU) at 6 months were recorded.

RESULTS

Three hundred seventy-nine (120 men) asthmatics completed the study. The ACT cut-off for uncontrolled and partly controlled asthma were ≤19 (sensitivity 0.74, specificity 0.67, % correctly classified 69.5) and ≤22, respectively (sensitivity 0.73, specificity 0.71, % correctly classified 72.1). Baseline ACT score had an odds ratio of 2.34 (95% confidence interval: 1.48-3.69) and 2.66 (1.70-4.18) for urgent HCU and exacerbations, respectively, at 6 months (P < 0.0001). However, baseline FeNO and spirometry values had no association with urgent HCU and exacerbations. The 3-month ACT score of ≤20 correlated best with step-up of asthma medications (sensitivity 0.65, specificity 0.81, % correctly classified 72.8). For serial changes of ACT scores over 3 months, the cut-off value was best at ≤3 for treatment decisions with low sensitivity (0.23) and % correctly classified (57.3%) values.

CONCLUSIONS

Single measurement of ACT is useful for assessing asthma control, prediction of exacerbation and changes in treatment decisions.

Asthma outcomes: composite scores of asthma control

BACKGROUND

Current asthma guidelines recommend assessing the level of a patient's asthma control. Consequently, there is increasing use of asthma control as an outcome measure in clinical research studies. Several composite assessment instruments have been developed to measure asthma control.

OBJECTIVE

National Institutes of Health institutes and federal agencies convened an expert group to propose the most appropriate standardized composite score of asthma control instruments to be used in future asthma studies.

METHODS

We conducted a comprehensive search of PubMed using both the National Library of Medicine's Medical Subject Headings and key terms to identify studies that attempted to develop and/or test composite score instruments for asthma control. We classified instruments as core (required in future studies), supplemental (used according to study aims and standardized), or emerging (requiring validation and standardization). This work was discussed at a National Institutes of Health-organized workshop convened in March 2010 and finalized in September 2011.

RESULTS

We identified 17 composite score instruments with published validation information; all had comparable content. Eight instruments demonstrated responsiveness over time; 3 demonstrated responsiveness to treatment. A minimal clinically important difference has been established for 3 instruments. The instruments have demographic limitations; some are proprietary, and their use could be limited by cost.

CONCLUSION

Two asthma composite score instruments are sufficiently validated for use in adult populations, but additional research is necessary to validate their use in nonwhite populations. Gaps also exist in validating instruments for pediatric populations.

Evaluation of association between exercise-induced bronchoconstriction and childhood asthma control test questionnaire scores in children

OBJECTIVE

Asthma control represents a major challenge in the management of asthmatic children; however, correct perception of control is poor. The aim of the study was to evaluate the association between subjective answers given to the Childhood Asthma Control Test (C-ACT) and objective evaluation of exercise-induced bronchonstriction (EIB) by standardized treadmill exercise challenge.

METHODS

EIB was evaluated by standardized treadmill exercise challenge and related to C-ACT scores in 92 asthmatic children.

RESULTS

Of the 92 studied children only six children had a concordance between a positive challenge test (ΔFEV1 ≥ 13%) and a positive response to the exercise-related issue of the C-ACT questionnaire (C-ACT total score ≤ 19). There was no significant association between the degree of EIB and the scores relative to the single question on exercise-related problems while a significant association was found when considering the whole questionnaire with C-ACT total score > 19 (r = -0.40, P < 0.001). The two single questions showing a significant association were those focusing on nocturnal asthma. The areas under the ROC curve (AUC) for the sum of the scores of these questions in relationship to a positive response to the exercise test was 0.74. The AUC of the C-ACT total score was 0.76 and 0.55 for the specific question on EIB related problems.

CONCLUSION

The discrimination power of the C-ACT total score in relationship to EIB was moderately good, and C-ACT questionnaire was capable of correctly predicting the absence of EIB in children reporting a global score > 19. However, direct questions on EIB are associated with a high number of false positive and negative responses; better associations are found questioning on the presence on nocturnal symptoms.

Association between the results of the childhood asthma control test and objective parameters in asthmatic children

OBJECTIVE

The Childhood Asthma Control Test (C-ACT), a seven-item, self-administered questionnaire, has been used as a tool to assess the control level in children with asthma. The aim of this study was to determine whether the C-ACT reflects airflow limitation and airway inflammation in addition to clinical manifestations.

METHODS

Asthmatic children aged 5-11 years who were able to perform the lung function test and fractional exhaled nitric oxide (FeNO) evaluation correctly were recruited during their regular visits. Children and their parents were asked to answer the officially developed Japanese version of the C-ACT.

RESULTS

Among 258 children (176 boys, median age 9 years), there was a significant positive correlation between the C-ACT score and the percent predicted forced expiratory volume in 1 s (%FEV(1)) (r = 0.317, p < .001). The accuracy of the C-ACT for identifying asthmatic subjects with normal lung function (%FEV(1) >80%) described as the area under the receiver operating characteristic curve was 71.5% (95% CI = 62.8-80.2%, p < .001), and based on the Youden index the optimal cutoff score was 23 (sensitivity of 78% and specificity of 54%). In contrast, there was no relationship between the C-ACT score and the FeNO value.

CONCLUSIONS

These results suggest that a cutoff score of 23 for the C-ACT could be useful for identifying children with well-controlled asthma and normal lung function. Further studies are warranted to develop an easy-to-use questionnaire to assess the extent of airway inflammation in children.