In response to recommendations from the 2010 National Institutes of Health Asthma Outcomes Workshop, we developed a system for measuring the negative impact of asthma on quality of life (QoL), which was referred to as the RAND Negative Impact of Asthma on Quality of Life (RAND-IAQL) item bank.
RAND Negative Impact of Asthma on Quality of Life Item Bank and Short Forms
The RAND Negative Impact of Asthma on Quality of Life item bank (RAND-IAQL-Bank) and short forms (RAND-IAQL-12 and RAND-IAQL-4) can help assess health-related quality of life in adult patients with asthma. Quality of life is defined in terms of how much asthma symptoms and impairments bother or matter to the patient. The item bank's 65 items cover a more comprehensive range of content areas than is typically assessed by asthma-specific quality-of-life measures.
To develop these items, RAND
- conducted focus groups of adults with asthma
- sorted their statements into thematic “bins”
- wrote items based on statements
- reviewed the literature to identify items to fill in content gaps
- obtained feedback from an expert panel
- conducted cognitive interviews
- and field-tested items on a national sample of more than 2,000 adults with asthma.
Psychometric evaluation of the field test data suggested that the concept of asthma impact on quality of life can be measured as a single underlying construct. A real-data simulated computer adaptive test suggests that highly precise scores can be obtained with as few as four to five items from the bank. From the item bank, we developed two short forms consisting of four and 12 items (reliability = .86 and .93, respectively).
Our methodological approach was informed by the standards for measure development set forth by PROMIS (Patient-Reported Outcomes Measurement Information System Collaborative), but deviated in our emphasis on developing items based on focus group content rather than prioritizing items in the existent research literature.
Items do not appear to confound quality of life with asthma symptomatology, control, or functional impairment.
Preliminary evidence supports the construct and discriminant validity of the two short-form measures. Our measures correlate highly with Marks' Asthma Quality of Life Questionnaire (AQLQ-M) and more strongly with the PROMIS global physical than mental scale. The impact of asthma on quality of life is greater in people with indicators of more severe asthma, less asthma control, and in people with greater asthma-related hospitalizations and emergency room visits.
Items covering a broad range of content were developed that can serve as a valid gauge of individuals' perceptions of the effects of asthma and its treatment on their lives.
The present work describes the process of developing an item bank and short forms that measure the impact of asthma on quality of life (QoL) that avoids confounding QoL with asthma symptomatology and functional impairment.
Correspondence Between the RAND-negative Impact of Asthma on Quality of Life Item Bank and the Marks Asthma Quality of Life Questionnaire 2014
The objective of this article was to provide an example of how to transform scores across disparate measures by using an item response theory (IRT)-based linking method.
The RAND-ACM, a five-item self-reported asthma control survey measure, performs well in a large ethnically-diverse sample of US adults with asthma and provides a cost-free alternative to other asthma control measures currently available.
The 65-items, item parameters, and short forms are public documents, available for free. Interested parties can develop their own short forms based on data from the full item bank, use the item parameters to create their own computer adaptive test (CAT), or use the CAT on our MMICTM (Multimode Interviewing Capability) website.
MMICTM is an open-source, web-based data collection system developed by RAND. Designed to manage the entire data collection process, MMICTM is an all-in-one online platform that guides researchers from survey development, sample recruitment, monitoring survey response rate, to producing a final dataset ready for analysis. Though MMICTM was originally limited to the administration of traditional modes of online data collection (e.g., fixed-length surveys), it has expanded to incorporate CAT capability. The RAND-IAQL item bank and short forms have been incorporated into MMICTM to allow for its seamless administration in the CAT environment.
Researchers interested in administering the RAND-IAQL item bank can either host MMICTM from their own server for free or outsource the entire survey development and administration process to RAND. Researchers who elect to outsource the data collection process often find it useful to consult with the RAND Survey Research Group, who can provide consultation on other aspects of the survey design and administration.