Health status measures are being used with increasing frequency in clinical research. Up to now the emphasis has been on the reliability and validity of these measures. Less attention has been given to the sensitivity of these measures for detecting clinical change. As health status measures are applied more frequently in the clinical setting, we need a useful way to estimate and communicate whether particular changes in health status are clinically relevant. This report considers effect sizes as a useful way to interpret changes in health status. Effect sizes are defined as the mean change found in a variable divided by the standard deviation of that variable. Effect sizes are used to translate "the before and after changes" in a "one group" situation into a standard unit of measurement that will provide a clearer understanding of health status results. The utility of effect sizes is demonstrated from four different perspectives using three health status data sets derived from arthritis populations administered the Arthritis Impact Measurement Scales (AIMS). The first perspective shows how general and instrument-specific benchmarks can be developed and how they can be used to translate the meaning of clinical change. The second perspective shows how effect sizes can be used to compare traditional clinical measures with health status measures in a standard clinical drug trial. The third application demonstrates the use of effect sizes when comparing two drugs tested in separate drug trials and shows how they can facilitate this type of comparison. Finally, our health status results show how effect sizes can supplement standard statistical testing to give a more complete and clinically relevant picture of health status change. We conclude that effect sizes are an important tool that will facilitate the use and interpretation of health status measures in clinical research in arthritis and other chronic diseases.

To investigate the prevalence of osteoarthritis (OA) of the knee in elderly subjects, we studied the Framingham Heart Study cohort, a population‐based group. During the eighteenth biennial examination, we evaluated the cohort members for OA of the knee by use of medical history, physical examination, and anteroposterior (standing) radiograph of the knees. Radiographs were obtained on 1,424 of the 1,805 subjects (79%). Their ages ranged from 63–94 years (mean 73). Radiographs were read by a radiologist who specializes in bone and joint radiology, and were graded 0–4 according to the scale described by Kellgren and Lawrence. OA was defined as grade 2 changes (definite osteophytes), or higher, in either knee. Radiographic evidence of OA increased with age, from 27% in subjects younger than age 70, to 44% in subjects age 80 or older. There was a slightly higher prevalence of radiographic changes of OA in women than in men (34% versus 31%); however, there was a significantly higher proportion of women with symptomatic disease (11% of all women versus 7% of all men; P = 0.003). The age‐associated increase in OA was almost entirely the result of the marked age‐associated increase in the incidence of OA in the women studied. This study extends current knowledge about OA of the knee to include elderly subjects, and shows that the prevalence of knee OA increases with age throughout the elderly years.

Summary: Worldwide, about 65 million people are estimated to have epilepsy. Epidemiologic studies are necessary to define the full public health burden of epilepsy; to set public health and health care priorities; to provide information needed for prevention, early detection, and treatment; to identify education and service needs; and to promote effective health care and support programs for people with epilepsy. However, different definitions and epidemiologic methods complicate the tasks of these studies and their interpretations and comparisons. The purpose of this document is to promote consistency in definitions and methods in an effort to enhance future population‐based epidemiologic studies, facilitate comparison between populations, and encourage the collection of data useful for the promotion of public health. We discuss: (1) conceptual and operational definitions of epilepsy, (2) data resources and recommended data elements, and (3) methods and analyses appropriate for epidemiologic studies or the surveillance of epilepsy. Variations in these are considered, taking into account differing resource availability and needs among countries and differing purposes among studies.

The cause of pain in osteoarthritis is unknown. Bone has pain fibers, and marrow lesions, which are thought to represent edema, have been noted in osteoarthritis. To determine whether bone marrow lesions on magnetic resonance imaging (MRI) are associated with pain in knee osteoarthritis. Cross-sectional observational study. Veterans Affairs Medical Center. 401 persons (mean age, 66.8 years) with knee osteoarthritis on radiography who were drawn from clinics in the Veterans Administration health care system and from the community. Of these persons, 351 had knee pain and 50 had no knee pain. Knee radiography and MRI of one knee were performed in all participants. Those with knee pain quantified the severity of their pain. On MRI, coronal T(2)-weighted fat-saturated images were used to score the size of bone marrow lesions, and each knee was characterized as having any lesion or any large lesion. The prevalence of lesions and large lesions in persons with and without knee pain was compared; in participants with knee pain, the presence of lesions was correlated with severity of pain. Bone marrow lesions were found in 272 of 351 (77.5%) persons with painful knees compared with 15 of 50 (30%) persons with no knee pain (P < 0.001). Large lesions were present almost exclusively in persons with knee pain (35.9% vs. 2%; P < 0.001). After adjustment for severity of radiographic disease, effusion, age, and sex, lesions and large lesions remained associated with the occurrence of knee pain. Among persons with knee pain, bone marrow lesions were not associated with pain severity. Bone marrow lesions on MRI are strongly associated with the presence of pain in knee osteoarthritis.

Objective. The goal of this project was to develop a more comprehensive and sensitive version of the Arthritis Impact Measurement Scales (AIMS).Methods. AIMS scale items were revised, and 3 new scales were added to evaluate arm function, work, and social support. Sections were also added to assess satisfaction with function, attribution of problems to arthritis, and self‐designation of priority areas for improvement. The new instrument was designated the AIMS2. A pilot test of format and content and a performance test of reliability and validity were carried out.Results. Questionnaire completion times in a pilot study of 24 subjects averaged 23 minutes, and evaluations were positive regarding the instrument's length and ease of completion, and the subjects' willingness to complete serial forms and return them by mail. Measurement performance was tested in 408 subjects: 299 with rheumatoid arthritis (RA) and 109 with osteoarthritis (OA); 45 of these subjects completed a second AIMS2 within 3 weeks. Internal consistency coefficients for the 12 scales were 0.72—0.91 in the RA group and 0.74—0.96 in the OA group. Test‐retest reliability was 0.78—0.94. All within‐scale factor analyses produced single factors, except for mobility level in OA. Validity analyses in both the RA and the OA groups showed that patient designation of an area as a problem or as a priority for improvement was significantly associated with a poorer AIMS2 scale score in that area. Reliability, factor analysis, and validity results were consistent in age, sex, and education subgroups. Satisfaction was moderately correlated with level of function in the same health status area, and the satisfaction items formed a reliable scale. Responses to the arthritis attribution items showed that most dysfunction in this sample was due to arthritis.Conclusion. The AIMS2 is a revised and expanded health status questionnaire with excellent measurement properties that should be useful in arthritis clinical trials and in outcomes research.