# Table 3 Hypothetical examples of combined data within scenarios

Arthroplasty Assessed outcome Effect of age Effect of BMI Effect of preoperative status Total effect on postoperative outcome (points)a
Scenario 1: A patient loses weight (X points) and increases preoperative status by Y points, this takes Z years
X, Y, Z = 5 (e.g. in 5 years BMI decreases from 30 to 25, KOOS HRQoL/ functioning/ pain increases from 35 to 40)
TKA HRQoL 0 0 5*0.51 2.6
Functioning 0 0 5*0.31 1.6
Pain 0 5*0.47 5*0.18 3.3
THA HRQoL 5*−0.08 5*0.23 5*0.37 2.6
Functioning 5*−0.33 5*0.35 5*0.22 1.2
Pain 5*−0.18 5*0.36 5*0.15 1.7
X, Y, Z = 10 (e.g. in 10 years BMI decreases from 35 to 25, KOOS HRQoL/ functioning/ pain increases from 35 to 45)
TKA HRQoL 0 0 10*0.51 5.1
Functioning 0 0 10*0.31 3.1
Pain 0 10*0.47 10*0.18 6.5
THA HRQoL 10*−0.08 10*0.23 10*0.37 5.2
Functioning 10*−0.33 10*0.35 10*0.22 2.4
Pain 10*−0.18 10*0.36 10*0.15 3.3
Scenario 2: A patient gains weight (X points) and decreases preoperative status by Y points, this takes Z years
X, Y, Z = 5 (e.g. in 5 years BMI increases from 25 to 30, HOOS HRQoL/ functioning/ pain decreases from 40 to 35)
TKA HRQoL 0 0 5*−0.51 −2.6
Functioning 0 0 5*−0.31 −1.6
Pain 0 5*−0.47 5*−0.18 −3.3
THA HRQoL 5*−0.08 5*−0.23 5*−0.37 −3.4
Functioning 5*−0.33 5*−0.35 5*−0.22 −4.5
Pain 5*−0.18 5*−0.36 5*−0.15 −3.5
X, Y, Z = 10 (e.g. in 10 years BMI increases from 25 to 35, HOOS HRQoL/ functioning/ pain decreases from 45 to 35)
TKA HRQoL 0 0 10*−0.51 −5.1
Functioning 0 0 10*−0.31 −3.1
Pain 0 10*−0.47 10*−0.18 −6.5
THA HRQoL 10*−0.08 10*−0.23 10*−0.37 −6.8
Functioning 10*−0.33 10*−0.35 10*−0.22 −9.0
Pain 10*−0.18 10*−0.36 10*−0.15 −6.9
1. aOn a 0–100 scale