Table 1.

Inclusion and Exclusion Criteria and Rationale for These Decisions

Inclusion Criteria	Rationale
≥ age 60	Prevention strategies (i.e., engagement and interventions) for older adults are different than for younger adults
Meets accepted clinical criteria for knee OA based on the American College of Rheumatology 1986 clinical criteria guidelines.28	We debated requiring radiographic evidence of knee osteoarthritis, but given that the clinical criteria (knee pain and 3 of the following: > 50 years old, < 30 minutes morning stiffness, crepitus on active motion, bony tenderness, bony enlargement, no palpable warmth of synovium) are what generate distress in patients (not abnormal radiographs), this approach to diagnosis seemed most relevant.
Western Ontario and McMaster University Arthritis Index (WOMAC) pain subscale score in the range of 7–15.	A lower score of 7 includes participants with clinically relevant symptoms of knee OA. For example, a score of 7 could be a patient with either moderate to severe symptoms on one or two items, or someone who may be minimally to moderately impaired on each item. Higher scores suggest either moderate difficulty with all items or severe impairment on several items. Participants with scores > 15 may have symptoms so severe that CBT or EXERCISE may not provide substantial benefit.
PHQ-9 greater than 0, with at least one of the cardinal symptoms of depression (low mood or anhedonia) endorsed.	Indicated prevention trials include individuals who are experiencing early or subthreshold symptoms of the condition of interest. We acknowledge that the majority of older adults with knee OA do not develop MDD or anxiety disorders. However, those with subthreshold depression, along with the knee OA, may be at increased risk of conversion to a syndromal depression or anxiety disorder. Requiring endorsement of depressed mood or anhedonia suggests that these participants may have a diathesis to a mood or anxiety disorder.
Modified Mini Mental State (3MS) Examination ≥>/= 80.30	Scores < 80 on the 3MS are highly suggestive of dementia. Scores ≥ 80 include participants with both normal cognition and mild cognitive impairment. To increase generalizability, we wanted to include participants with and without mild cognitive impairment. A prevention trial for individuals with dementia may require a different approach.
Has or is willing to establish care with a personal physician prior to any experimental procedures.	Because participants may be randomized to EXERCISE, which includes aerobic conditioning as part of a home exercise program, for participant safety (in particular cardiac safety), we required permission of their primary care physician for participation.
Exclusion Criteria
Episode of MDD within the past year.	As this is a study of indicated depression prevention, we did not want to enroll participants currently experiencing a partially treated episode of MDD. The lack of MDD within the past year was established by SCID.
Currently taking an antidepressant	Current use of antidepressant pharmacotherapy could prevent new onset MDD and anxiety disorders above any effect from CBT or EXERCISE.
Currently taking an anti-anxiety medicine > 4 times/week for the past 4 weeks.	Sustained use of anti-anxiety medicine could prevent new onset anxiety disorders.
Lifetime history of bipolar disorder or schizophrenia, or substance use disorder within the past 12 months.	These individuals require treatments beyond the scope of a depression prevention project.
Receiving knee-related workers compensation or involved in knee pain-related litigation.	Individuals involved with these kinds of litigation may experience secondary gain that could interfere with improvement.