Table 2 Relative risk ratios (95% confidence intervals) for work impairment trajectory class membership from multinomial logit model and the relative importance in predicting trajectory class membership from dominance analysis

Female sex (male = ref)

1.11 (0.89, 1.38)

1.23 (1.01, 1.49)

0.0006

10

Age (24–50 years = ref)

1.0

1.0

0.0011

9

 51–60 years

0.94 (0.73, 1.23)

1.13 (0.90, 1.42)

 61–65 years

1.05 (0.78, 1.41)

1.32 (1.01, 1.71)

Hip as index joint (knee = ref)

0.82 (0.67, 0.99)

1.23 (1.04, 1.45)

0.0033

7

Education (Less than high school = ref)

1.0

1.0

0.0144

2

 High school

2.24 (1.37, 3.66)

1.23 (0.88, 1.74)

 College/university

4.96 (3.04, 8.11)

1.85 (1.31, 2.61)

Body mass index (< 25 = ref)

1.0

1.0

0.0127

3

 25–29

0.68 (0.54, 0.86)

0.92 (0.74, 1.14)

 30–34

0.48 (0.37, 0.64)

0.67 (0.52, 0.85)

 35 + 

0.39 (0.27, 0.59)

0.79 (0.58, 1.08)

Diabetes

1.19 (0.70, 2.01)

0.88 (0.57, 1.36)

0.0003

12

Lung diseases

1.18 (0.83, 1.68)

0.95 (0.70, 1.30)

0.0004

11

Balance troubles

1.22 (0.59, 2.49)

1.14 (0.64, 2.01)

0.0002

14

Rheumatoid arthritis

0.50 (0.28, 0.90)

0.70 (0.45, 1.09)

0.0015

8

Cardiovascular diseases

0.91 (0.51, 1.64)

1.12 (0.68, 1.85)

0.0002

13

Walking difficulties

0.44 (0.29, 0.68)

0.81 (0.58, 1.13)

0.0046

6

General health

1.24 (1.18, 1.31)

1.10 (1.05, 1.15)

0.0122

4

Pain

0.47 (0.44, 0.50)

0.61 (0.58, 0.64)

0.0869

1

Physical function

1.04 (1.02, 1.06)

1.01 (0.99, 1.03)

0.0062

5

McFadden pseudo-R²

0.145

MCC

0.271

CEN

0.581

PDI

0.600