Table 1 Severity of symptoms and medications used during the month prior to assessment at baseline and 36 months

Pain NRS in most painful knee, mean ± SD

5.5 ± 2.4

5.4 ± 2.4

4.8 ± 2.8

Prescription analgesic used at any time

30.1%

29.4%

24.2%^a

Prescription or OTC analgesic used frequently^b

47.8%

47.9%

42.9%

Nutraceuticals used frequently^b

41.3%

43.4%

36.0%^a

Number of medications          Analgesics

0:

52.2%

52.1%

57.1%

used frequently^b

1:

36.0%

37.6%

33.3%

2:

9.9%

8.8%

7.8%

≥3:

1.9%

1.5%

1.8%

                                         Nutraceuticals

0:

58.7%

56.6%

64.0%^a

1:

4.1%

4.2%

4.1% ^a

2:

30.1%

31.5%

22.8% ^a

≥3:

6.8%

7.7%

9.1% ^a

Patient-reported medication use:

   Acetaminophen^b

13.5%

12.5%

14.4%

   Prescription NSAIDs^b

8.2%

8.1%

9.3%

   OTC NSAIDs^b

26.8%

26.7%

21.3%^a

   Coxibs^b

10.2%

9.8%

4.7%^a

   Opioids^b

3.3%

3.0%

5.0%

   Chondroitin and/or Glucosamine^b

40.7%

42.9%

35.4%^a

   Other nutraceutical^b

8.6%

8.8%

10.2%

   Intra-articular steroid injection^c

4.2%

4.3%

7.3%

   Intra-articular hyaluronan injection^c

2.0%

1.7%

3.3%

Medications brought into visit or identifiedd:

N = 820

N = 690

N = 690

   Proton pump inhibitor/H2 antagonist

11.2%

9.4%

21.4%

   NSAID

7.7%

6.6%

13.9%

   Coxib

11.6%

9.3%

5.2%

   NSAID + PPI (% of NSAID users)

7.2% (6/83)

9.4% (5/53)

26.0% (25/96)

   Coxib + PPI (% of coxib users)

34.9% (29/83)

30.7% (23/75)

41.7% (15/36)