Table 1 Independent variables used in the linear regression analyses, variables and instruments used for data collection, and categorisation of the variables

Age

Continuous

Sex

Female/Male

Coping capacity:

Sense of Coherence Scale [30]

Continuous or

Weak: 13–54 points/Moderate to Strong: 55–91 points [31]

Education:

Interview

Primary or lower secondary level/High School or University

Degree of MS disability^a:

Expanded Disability Status Scale [18]

Mild: 0–3.5/Moderate: 4.0–5.5/Severe: 6.0–9.5

Type of MS^b

Relapsing/remitting MS/Progressive MS

Time since MS diagnosis^c

Continuous

Immunomodulatory treatment^c

Yes/No

Mood:

Beck Depression Inventory II [32]

No depressive symptoms: <13/Depressive symptoms: ≥13 [28]

Cognitive function:

Symbol Digit Modalities Test [33]^d

Age-related norms, written or oral reply. No impairment: < −1.5 SD from the mean/Impairment: ≥ −1.5 SD from the mean [33]

Manual dexterity:

Nine Hole Peg Test [34]^e

No impairment: ≥0.5 pegs/sec/Impairment: <0.5 pegs/sec [33]

Walking ability

Walk without aid/Walk with aid/Cannot walk

Personal activities of daily living:

Barthel Index [35]

Independent: 100 points/Dependent: < 100 points

Personal and instrumental activities of daily living:

Katz Extended ADL Index [36]

Independent: 20 points/Dependent: < 20 points

Frequency of social/lifestyle activities:

Frenchay activities index [37]

Age-, sex-related norms. No impairment: >25^th percentile/Impairment: < 25^th percentile [38]

Progress in MS disability:

Expanded Disability Status Scale

No change: ≤1 points change/Change: >1 points change