Table 2 Study questionnaires

 Section A: knee pain

Duration

Pain in last 12 months. Left, right

Time since onset

< 1 year, 1–4 years, 5–9 years, 10+ years. Left, right

Pattern [36]

5 flare pattern illustrations. Left, right

Experience of knee pain [37]

In past 6 months: no pain, predictable pain, some unpredictability, constant. Left, right

Walking difficulty [38]

Injury induced walking problems for at least 1 week. Left, right

Pain, aching, stiffness in last month [39, 40]

No days, few days, some days, all days. Left, right

Worst/least in last week, average, current [41]

0–10 NRS with anchors (no pain, pain as bad as you can imagine)

Flare-up at present

Yes/no. Left, right

Self-reported main flare trigger

Free text

Bothersomeness in last 24 h [42]

Not at all, slightly, moderately, very much, extremely. Left, right

Leg angles [43]

Very bow legged, bowed legged, normal, knock-knee, very knock-knee. Left, right

Foot angles [43]

Very turned out feet, turned out feet, straight, turned in feet, very turned in feet. Left, right

KOOS-PS [44]

7-item and 5-option categories for difficulties with daily activities in last week

KOOS-Qol [45]

4-item and 5-option categories for quality of life in last week

Medications for knee pain, last week

Health professional consultation for knee pain, last year

17-option categories for drug use

General practitioner, practice/district nurse, physiotherapist, surgeon, rheumatologist, acupuncturist, occupational therapist.

 Section B: general health

Perceived general health [46]

Physical activity(GPPAQ) [47]

Excellent, very good, good, fair, poor

Work physical activity (5-response options), general physical activity in last week (5-response options, 4-option categories), walking pace

Self-reported weight

Stones/lbs. or kg

Self-reported height

Feet/inches or cm

 Section C:

demographics

Gender

Date of birth

Current employment

Male/female

Date/month/year

Paid employment or self-employed, retired, looking after home and/or family, unable to work because of sickness or disability, unemployed, doing unpaid or voluntary work, full or part-time student

 Knee pain

Flare-up at present

Yes/no. Left, right

Average pain in last 24 h [27]

0–10 NRS with anchors (no pain, pain as bad as you can imagine). Left, right

 Changes noticed since flare-up†

Limping, swelling, stiffness, increased difficulty with activities of daily living, sleep disturbed by knee pain

Tick as many boxes as apply

 Physical activities

Vigorous physical activity > 10 mins [48]

Yes/no

Climbing several flights of stairs

Yes/no

Repetitive or prolonged squatting

Yes/no

Repetitive or prolonged kneeling

Yes/no

Climbing up and down ladders

Yes/no

Lifting or moving heavy objects

Yes/no

Prolonged periods of sitting without a break

Yes/no

Prolonged periods of standing without a break

Yes/no

Any unusual activities involving knees

Yes/no

 Slips, trips, sprains, strains

Slip, trip, or fall

Episode of buckling or giving way [49]

Yes/no

Yes/no. Left, right

 Health and healthcare

Reduce or miss medication

Take extra medication

Yes/no

Yes/no

Cough, cold, other minor infection

Yes/no

 Stress and other things

Work related stress [50]

Home related stress [50]

Yes/no

Yes/no

Friend/family-related stress [50]

Yes/no

Low mood/depression

Yes/no

Feeling angry, irritable, hostile

Yes/no

Poor night’s sleep

Yes/no

Eat foods usually avoided

Yes/no

Cold/damp weather

Not at all, slightly, moderately, severely, extremely

 Day of above exposure

All yes responses from above sections (physical activity; slips, trips, sprains, strains; health and healthcare; stress and other things) anchored to day of the week

Grid of previous 7 days from declared flare-up onset. Tick as many boxes as apply

 Knee pain

Average pain in last 24 h [27]

0–10 NRS with anchors (no pain, pain as bad as you can imagine). Left, right

 Impact of pain

Bothersomeness in last 24 h [42]

Not at all, slightly, moderately, very much, extremely. Left, right

 Medication use

Pain medication taken in last 24 h

No; yes, but less than usual; yes, but about the same as usual; yes, more than usual

 Flare-up resolution

Has your flare-up ended

Yes/no

 Main flare-up trigger

Did your main trigger for a flare-up of knee pain [baseline response reminder] happen today

Yes/no

 Knee pain

Average pain in last 24 h [27]

0–10 NRS with anchors (no pain, pain as bad as you can imagine). Left, right