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Measuring health outcomes: An empirical comparison of adaptive and standard questionnaires
RS2002/03-DG16
Final Report Date: June 2005
| Principal Investigator: | Jacek Kopec (Arthritis Research Centre of Canada) | |
| Co-investigators: |
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For more information about this study, please contact Dr. Jacek Kopec.
Issue
Clinical trial researchers and epidemiologists use various questionnaires to measure the health outcomes of back pain patients. Compared with the standard paper and pencil questionnaires generally used, computer-based testing has the potential to make health outcomes questionnaires more flexible and precise and easier for patients to fill out.
In this project, researchers used computerized adaptive testing (CAT) technology to develop an adaptive questionnaire for measuring health outcomes in low back pain patients, and evaluated its reliability and usability.
Key findings
- The adaptive questionnaire is feasible, reliable and valid. It required participants to answer fewer questions, while allowing a level of precision that is comparable to that of standard questionnaires.
- The new questionnaire has the potential to improve the cost, efficiency and precision of outcome assessment in back pain, and to make it easier to compare health outcomes data across different studies and conditions.
Objectives
- To develop a computerized adaptive questionnaire to measure health outcomes in patients with back pain and assess its feasibility, reliability and efficiency.
- To compare the questionnaire’s measurement properties with those of standard back pain questionnaires and a generic health questionnaire.
Method
A sample of back pain patients from the Vancouver General Hospital Combined Spine Program completed a web-based questionnaire that included both the new adaptive questionnaire and standard questionnaires currently in use. A smaller number of the participants also completed a follow-up questionnaire.
Participants could fill in the questionnaire at home, in a telephone interview, or in person at the Arthritis Research Centre of Canada (ARC).
Scores were computed for the adaptive questionnaire and the other standard questionnaires. Reliability was measured by test-retest reliability assessment, that compared the initial questionnaire responses with those of the follow-up questionnaire. Data analysis also included calculation of an overall health utility score and measures of relative efficiency for the adaptive questionnaire and each type of standard questionnaires.
Results
The adaptive questionnaire had comparable ability to assess levels of pain/discomfort, satisfaction with current symptoms, duration of current episode, daily activities, walking and overall health utility score as the standard questionnaires. The test-retest reliability results and other measures confirmed the reliability and validity of the adaptive questionnaire.
Conclusions
The adaptive questionnaire is feasible, reliable, valid and efficient. It is able to measure health outcomes with comparable levels of precision to standard questionnaires now in use. It has the potential to simplify outcome assessment in back pain, reduce the cost of data collection and improve data quality. The adaptive questionnaire also includes a health utility score that can be used in economic analyses.
Future directions
Future studies are needed to confirm these results, and to assess the adaptive questionnaire’s sensitivity to changes that occur over time. Future work can also incorporate lessons learned and feedback from participants about making the web-based delivery of the adaptive questionnaire easier for participants.
Publications
Kopec JA, Sayre EC, Davis AM, Badley EM, Abrahamowicz M, Sherlock L, Williams JI, Anis A, Esdaile JM. Assessment of health-related quality of life in arthritis: Conceptualization and development of five item banks using item response theory. Health Qual Life Outcomes 2006 Jun 2;4(1):33