To compare the effectiveness of an osteoarthritis of the knee self-management education program delivered by health professionals with a control group, as determined by improvements in pain, quality of life and physical function.
A two group randomized, controlled repeated measures study design will compare the osteoarthritis of the knee program (OAK) with a similar group of control participants. Independently of the study all participants will be able to receive standard medical management of OA knee. In addition, the intervention group will participate in a disease specific knee osteoarthritis self-management program (OAK). Blinding of participants will not be possible due to the nature of the intervention; however, assessors will be blinded to group allocation. The OAK program will be conducted in a community setting at Arthritis Western Australia.
People with osteoarthritis of the knee who complete the OAK Program will report improved quality of life, improved knee function and decreased pain compared with those managed conventionally.
This study has been approved by the Human Research Ethics Committee at Curtin University of Technology (HR141, 2002). All participants will provide written informed consent prior to randomisation. Data access and storage will be in keeping with National Health and Medical Research Council guidelines, as approved. License agreements have been obtained for SF-36 Questionnaire and WOMAC Questionnaire. This trial is registered with the Australian and New Zealand Clinical Trial Registry, number: 12607000080426.
146 participants with established OA of one or both knees will be recruited into the study. As the OAK program is generally provided as a clinical service, subjects will be recruited from among people presenting to enroll in the OAK program. The operational definition for OA knee is diagnosis by a medical practitioner based on either clinical examination or radiological evidence. Disease severity is not a selection criterion. Exclusion criteria will be rheumatoid arthritis or other inflammatory joint disease; knee surgery planned within 6 months of commencing the study; physical impairments that preclude full participation; inability to communicate in English within a group setting or aged ≤ 18 years (Table ). During the recruitment phase the program will be actively promoted to general practitioners and rheumatologists through professional societies, and to the general public through advertising and media coverage.
Volunteers for the study will be randomized to an intervention group (immediate start) or a control group (delayed start). As there is evidence that SM is an effective addition to usual care [5
], all volunteers randomized to the control group will be offered the intervention at the completion of the 6-month control period.
Volunteers will be randomized in blocks to ensure manageable numbers for intervention groups. Pre-prepared cards indicating group assignment will be placed in sealed opaque envelopes and drawn as a lottery by a third party for allocation to treatment groups. In order to ensure optimum group sizes, allocation will not take place until a whole block has been recruited
The OAK program will be conducted over a 6-week period enabling participants to incorporate and consolidate information learned from week to week. In addition to the weekly sessions, participants will be given printed information relevant to the course component discussed each week. Program leaders will be health professionals including nurses, physiotherapists, and occupational therapists that have the knowledge and skills to present information on disease specific topics and accurately respond to complex questions. It is necessary that health professionals who deliver this program meet minimum musculoskeletal knowledge requirements. The fidelity of the OAK program will be maintained by the use of a facilitator's manual with modules for program delivery each week.
To facilitate optimum group dynamics, the target group size will be 12 participants, although this may vary from 8 to 16 depending on recruitment and randomisation. The program approach is holistic and will not exclusively focus on one aspect of care. Self-management constructs will be employed to promote behavioral changes that will be aimed at optimizing participants' health status. Goal setting and the development of strategies to achieve these goals long term [11
] will be emphasized in the program. Participants will be encouraged to set their own goals related to health areas that they identify as requiring improvement.
Topics that will be covered in the weekly sessions include:
• Pain management strategies (cognitive and pharmaceutical)
• Joint protection
• Correct use of analgesia/medications
• Balance/falls prevention/proprioception
• Cognitive techniques
• Nutrition/weight control
• Self-management skills
• Team approach to health care
• SMART goals (Specific, Measurable, Achievable, Realistic, Time-framed)
Assessments and Procedures
Assessments will be performed by 2 physiotherapists blinded to group allocation; conducted one week prior to the first self-management session (baseline) and on the week following the sixth and final session (week 8). The physiotherapists performing assessments will have no contact with the participants other than during the assessment sessions and will not participate in facilitation of the program. Participants will be assessed by the same physiotherapist whenever possible to ensure consistency.
Members of the control group will also attend assessments at baseline, and week 8. All volunteers will be assessed again 6 months after randomisation. In keeping with intention to treat principles, all participants will be encouraged to attend for follow-up measurements regardless of level of attendance at the self-management intervention. Self reported questionnaires (WOMAC, SF-36, VAS pain) would be mailed out to participants that are unable to attend assessment visits. Program and assessment attendance (at all time-points) will also be collected and collated.
Demographic information will include age, sex, co-morbidities and socioeconomic information. Socio-economic scales will be compiled using "The Index of Relative Socio-Economic Disadvantage" scales [12
]. This index provides a weighted value that includes variables that reflect or measure disadvantage. These variables include: low-income, low educational attainment, high unemployment and low skilled occupations.
The dependent variables for the study are listed below.
• Health status; measured using the WOMAC Osteoarthritis Index for OA of the knee (WOMAC LK3.0). Also self-administered, the WOMAC assesses pain, stiffness and physical function [13
] and can be completed in less than 5 minutes. Two major studies have shown WOMAC pain, stiffness and physical function subscales are valid and the questionnaire is reliable and sensitive enough to detect changes in health status following a variety of interventions [14
• Quality of life; measured using the Short Form 36v1 (SF-36) questionnaire. This 36 item questionnaire is self administered, and can be completed in about 15 minutes [16
]. Scores for 8 sub components reflecting both physical and mental status can be generated. Reliability and validity have been established in numerous studies [16
• Active range of motion of the knee joints; measured using a long armed Goniometer [18
]. The reliability and validity of the goniometer to measure range of motion has been widely documented for knee flexion and extension [18
• Strength of the hamstrings and quadriceps muscles will be measured using a Mecmesin Force Gauge Dynamometer. The dynamometer will be fixed via an adjustable arm to a portable steel frame and stool. Subjects will sit on the stool with hips and knees flexed to 90 degrees. Isometric strength in flexion and extension will be measured in this position. Each knee will be measured 3 times. The first measurement will be a practice and will be excluded from analysis. The two subsequent measures will be averaged for analysis.
• Pain will be assessed at weekly intervals from baseline to the 8-week follow-up assessment. (See Figure : Study Design Flow Chart). A 10 cm Visual Analog Scale (VAS) anchored at the left with "no pain" and at the right "worst pain imaginable" will be used for this assessment. The VAS is well established in clinical practice and research for measuring pain levels in arthritis populations [20
• Functional mobility, using a Functional Knee Assessment Test (FKAT) will be assessed using a modification of the "Timed Up and Go" test (TUG). TUG is widely used to assess basic functional mobility in the elderly [21
]. The test measures the time taken to stand from a chair and walk 6 m, turn around, return to the chair and sit down. For this study the addition of ascending and descending a 15 cm step will be added to the outward walk.
Statistical Power Calculation
A priori power calculations for this study will be based on the quality of life outcome as measured by the SF-36. Sample size was calculated according to guidelines in the SF-36 Users Manual to determine differences in changes over time between the intervention and control groups using a repeated measures design allowing an inter temporal correlation between scores of 0.60 [16
]. The pilot study SF-36 data showed an average improvement of 10 points across the eight domains measured. Assuming this level of improvement is achieved in the intervention group and there is no change in the control group and allowing for a 10% drop out rate, the number of participants required per group will be 60 [16
]. In the pilot study, there was a drop out rate of 5% over 3 years, so allowing 10% is a conservative estimate. Differences in changes in functional ability measured using the WOMAC, similar in magnitude to those previously documented [24
] would also be detectable in a sample of this size.
Data will be analyzed in a blinded manner. Treatment groups will be examined for comparability at baseline. Main comparisons between treatment groups will be performed using an intention to treat analysis. To test the effects of treatment, between group differences in changes over time will be examined using repeated measures ANOVA. Separate analysis will be conducted for each outcome variable. Statistical significance will be inferred at a 2-tailed p < 0.05. Results will not be adjusted for multiple comparisons as all outcomes of interest have been nominated a priori and such adjustment would likely render all findings of interest, despite their clinical importance, non-significant.