Asthma outcomes: Composite scores of asthma control

Abstract

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 (NIH) 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 (MeSH) 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 an NIH-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.

Asthma Control Assessment Tools

“…[37][38][39][40] In the developmental study, Liu et al 36 reported that the cACT overall score discriminated between patients who differ in the specialists' rating of asthma control. Similarly, Chen et al 37 reported that mean cACT scores were significantly lower among patients with poor asthma control as compared with those who were well controlled according to specialists' rating.…”

“…14,40,47 The ACQ was developed specifically to quantify levels of asthma control defined by international guidelines (ie, the British Thoracic Society 1990 guidelines for management of asthma in adults, 48 the National Heart, Lung, and Blood Institute 1992 international consensus report on diagnosis and treatment of asthma, 49 and the Thoracic Society of Australia and New Zealand 1989 asthma management plan). 50 The ACQ involves asking patients to recall their experiences in the previous week and to respond to 6 questions on a 7-point scale about 5 asthma symptoms (nighttime waking, symptoms on waking, activity limitations, shortness of breath, and wheezing) and about the frequency of using short-acting ␤ 2 agonists.…”

“…40 The ACQ has been validated for use as a self-administered tool in-person, at home, or by telephone. 40 Moderate to strong correlations resulted from comparing the ACQ with the AQLQ (r ϭ 0.76), 54 Mini Asthma Quality of Life Questionnaire (r ϭ 0.72 and 0.74), 55 the Medical Outcomes Survey Short Form-36 (SF-36) (r ϭ 0.19 -0.55), 56 and the ACT (r ϭ Ϫ0.82 to Ϫ0.89). 13,14,19 The correlations between the ACQ and the shortened versions were high (r ϭ 0.87 with ACQ-5, 0.98 with ACQ6a, and 0.92 with ACQ-6b).…”

“…Respondents are graded as either having or not having a control problem in each one of these 4 items; the item scores are then summed to provide a total, which ranges from 0 (no asthma control problems) to 4 (4 asthma control problems). 8,40,66,67 Skinner et al 71 developed a parent completed ATAQ version to identify children and adolescents (5-17 y old) with current problems in asthma control. This version was derived from the adult version developed by Vollmer et al 66 …”

“…40 Vollmer et al 66 reported that only 2% of those with an ATAQ score of 0 had been hospitalized for asthma in the past year, versus 24% of those with an ATAQ score of 4. In a 12-month prospective study, 67 subjects with ATAQ scores of 3 or 4 (ie, 3 or 4 control problems) were 5 times more likely to be hospitalized, 5.4 times more likely to be seen in an emergency department, and twice as likely to have routine asthma care visits compared with subjects with no control problems.…”