Researchers in the US tested whether specific or general questions were better at reflecting improvement following treatment of patients with knee osteoarthritis.
Osteoarthritis of the knee is an irreversible condition that can be painful and affect quality of life. In knee osteoarthritis, the normal structure of the joint that resists bone-on-bone contact during standing or movement is progressively destroyed, resulting in pain, stiffness, decreased mobility, and swelling. Much research is directed towards understanding knee osteoarthritis and finding ways to improve mobility and function.
In order to fully determine whether a certain type of treatment has been useful or not, researchers have to be able to assess whether or not there has been an improvement. This is frequently done by asking patients to report on their function by asking questions that determine whether they have difficulty completing certain tasks, such as coming to sit at the side of a bed, or running to catch a bus.
Computer Adaptive Testing
A superior type of computer-generated questioning has been developed, called computer adaptive testing (CAT). It is designed to ask questions in a way that an experienced clinician would do. The questions are generated based on the patient’s previous answer to try and obtain the most accurate information on function. Researchers of osteoarthritis have the choice of two different CATs to use: one is more generic and can be asked to patients with a range of different conditions, and one is developed specifically for use in osteoarthritis. A Boston-based research group designed a study to provide information on which test would be best at revealing the true degree of improvement following treatment and published their findings in BMC Musculoskeletal Disorders.
The researchers obtained questionnaire results from 104 patients with knee pain, who were already diagnosed with knee osteoarthritis. They were asked to answer both generic and specific CAT questions before and after a six-week exercise program designed to improve their ability to move their knee. An example of a specific question used is “Because of arthritis in your legs, how much difficulty did you have on an average day, when…?” An example of a generic question is “Does your health now limit you in…?”
Both Questionnaires Were Effective
The researchers found that there was no significant difference between the two types of questions when looking to see if an improvement had occurred. The specific questionnaire took on average 2.76 minutes to complete, which was on average approximately one minute longer than the generic questions. The results, however, suggested that when only a small number of patients are included in clinical trials it might be better to use the specific questions because they may better reflect the impact of osteoarthritis on function.
Limitations do exist in how far the data from this study can be interpreted. The researchers compared only the two tests with each other and not any other accepted methods of reporting improvement or a medical assessment by a clinician. Additionally, the study period was only over six weeks and often a longer period is needed to detect a change in chronic conditions. Debate on whether specific or generic questioning is better in clinical trials is found frequently in the medical literature. The results of this study indicate that both types have potential usefulness in evaluations of knee osteoarthritis.
Written by Nicola Cribb, VetMB DVSc Dip.ACVS
(1) Chang F-H, Jette A, Slavin M, Baker K, Ni P, Keysor J. Detecting functional change in response to exercise in knee osteoarthritis: a comparison of two computerized adaptive tests. BMC Musculoskeletal Disorders 2018;19:29.
(2) Jette A, Haley S. Contemporary measurement techniques for rehabilitation outcomes assessment*. Journal of Rehabilitation Medicine 2005;37:339–45.