Table 1 Description of questionnaires

Problem Areas in Diabetes questionnaire (PAID) [21]

Self-reported questionnaire consisting of twenty statements identified as common negative emotions related to living with diabetes.

Each item is rated on a 5-point Likert scale, ranging from 0 (“not a problem”) to 4 (“a serious problem”). The total score is transformed to a 0–100 scale, with higher score representing higher distress.

WHO-Five Well-being Index (WHO-5) [46]

The five items covering positive mood (good spirits, relaxation), vitality (being active and waking up fresh and rested), and general interests (being interested in things) in the past two weeks.

The degree to which these feelings were present is rated on a 6-point Likert scale, ranging from 0 (“not present”) to 5 (“constantly present”)

The scores are transformed to a 0–100 scale, with higher score representing better well-being.

Euroqol 5 Dimensions (EQ-5D)/Euroqol Visual Scale (EQ-VAS) [47]

The EQ-5D measures general health status on five dimensions:

The EQ-5D scores was computed using the MVH-A1 algorithm

1) Mobility

Range -0.594 to + 1.00

2) Self-care

0: (equal to) death

3) Usual activities

1: full health

4) Pain/discomfort

Negative values: a health score worse

5) Anxiety/depression

than death

The EQ-VAS measures the overall health state on a graded, vertical line.

Range 0 to 100

0: worst imaginable health state

100: best imaginable health state.

Hospital Anxiety and Depression Scale (HADS) [48]

A questionnaire measuring anxiety (7 items) and depression (7 items)

Each item is rated on a 4-point Likert scale, ranging from “Most of the time” to “not at all”.

Sum scores for each subscale 0–21, higher score indicate more severe anxiety/depression.

International Physical Activity Questionnaire (IPAQ) [49]

29 Items measure how many days’ physical activities are performed during the past seven days in four domains (work, transportation, housework and leisure-time)

Measuring domain-specific activity scores. A total physical activity score is calculated as the sum of the number of minutes of total moderate activity for each subdomain, plus two times the number of minutes of total vigorous for each subdomain.

Active Engagement, Protective Buffering and Overprotection (ABO) [50]

Measuring overprotection by the partner. Five items measure active engagement, eight items measure protective buffering and six items measure overprotection.

Each items is scored on a 5-point Likert scale, ranging from 1 (“never”) to t 5 (“very often”).

Total score: 15-95

Summary of the Diabetes Self-Care Activities Measure (SDSCA) [51]

Eleven items assessing several aspects of the diabetes regimen: general diet, specific diet, exercise, blood glucose testing, foot care, and smoking. Items measure how many days a patient has performed self-care activities in the last seven days.

Ten items are rated on an 8-point Likert scale, measuring how many days an activity is performed in the last week. One items measures smoking status (yes/no) and the amount of cigarettes smoked in the last week. Each of the domains is measured separately.

Diabetes Coping Measure (DCM) [52]

Four scales measuring diabetes coping: tackling spirit, avoidance, passive resignation and diabetes integration.

The 20 items are measures on a 5-point Likert scale, ranging from 1 (“disagree”) to 5 (“agree strongly”)

Higher scores on tackling spirit and diabetes integration indicate more adaptive coping. Higher scores on passive resignation and avoidance indicate poor coping.

Confidence in Diabetes Self-care questionnaire (CIDS) [53]

Questionnaire adapted to type 2 diabetes patients. Twenty items measure diabetes-specific self-efficacy.

Each item is scored on a 5-point Likert scale ranging from 1 (“No, I don’t believe I’m able to do this”) to 5 (“Yes, I’m sure I’m able to do this”).

The total score is transformed to a 0–100 scale, with higher score indicating higher self-efficacy.

Illness Perception Questionnaire (IPQ) – short version [54]

Questionnaire assessing the cognitive representation of illness, focuses on seven scales, assessing (1) Timeline acute/chronic and (2) Timeline cyclical (3) Consequences (4) Personal control (5) Treatment control (6) Illness coherence (7) Emotional representation

Eight questions answered on an 11-point Likert scale, ranging from 0 to 10, with the scale for each question having a different meaning. For example when measuring concerns about the illness, the scale ranges from 0 (no at all concerned) to 10 (extremely concerned). The three most important causes of the illness are measured with an open ended question.