Table 2 Measures assessed by PCPs

Sex, age, date of establishment, medical degree, additional degrees, type of medical office (community practice, solo practice etc.)

✓ IG, CG

Number of patient contacts and health checks (Check-up 35) per quarter

✓ IG, CG

Counseling process^b

Motivation and implementation of prevention strategies in general

We use a set of questions from the validated nationwide survey on modifying health behavior to prevent cardiovascular diseases among German PCPs (ÄSP-Study) [45]:

a) Frequency of provision of lifestyle advice of weight reduction, increasing physical activity, achieving a healthy diet, quitting smoking, and some further measures of risk factors on a 5-point Likert scale (no provision - provision to all patients)

b) perceived importance of reduction of risk factors is rated on a 4-point Likert scale (very important - not important at all)

c) PCPs self-rated competence to motivate patients changing lifestyle is also rated on a 4-point Likert scale (very high - very low)

d) The level of PCPs’ agreement to statements regarding attitudes, self-competence, and self-efficacy of PCPs is rated on a 4-point Likert scale (completely agree - completely disagree)

e) Cooperation’s to other institutions and experts regarding prevention

In addition, questions on obstacles of counseling were derived from two qualitative studies on lifestyle counseling in diabetes care and obese patients [46, 47]

✓ IG, CG

Content of counseling with participant

After each routine health check with a study participant PCPs are asked about the content of counseling (counseling, information material, and referral to expert) regarding weight reduction, increasing physical activity, achieving a healthy diet and quitting smoking using tick boxes. The framework is adopted from two studies [45, 48].

✓ IG, CG

Future medical appointments

Question, if a medical appointment was arranged and when. This aspect was identified in an earlier focus group with PCPs in the planning phase of the trial.

✓ IG, CG

Modified questionnaire to assess shared decision making for diabetes prevention opportunities including six questions. Five questions are ranked on a 6-point Likert scale (completely disagree-completely agree), and one overall question. The original questionnaire PEF-FB-doc [49] is the pendant to PEF-FB-9 and was developed and validated for clinical encounters in the primary health care setting and people with an existing medical decision.

✓ IG, CG

Acceptance of diabetes risk score^b

Use of diabetes risk scores

Question adopted from the ÄSP-Study [45] about which diabetes risk scores are known and used in everyday practice.

✓ IG, CG

Attitude towards diabetes risk scores

Different questions regarding the usefulness, validity, understandability and acceptance towards the diabetes risk score. Questions were adapted from a qualitative study by Müller-Riemenschneider et al. [10] and a systematic review by Dhippayom et al. [5]. Usefulness is rated on a 5-point Likert scale (not useful – very useful), all other questions are rated on a 4-point Likert scale (completely agree - completely disagree)

✓ IG

(CG: question about usefulness only if PCP knows diabetes risk scores)

The PCP measures waist circumference, weight, and height from each participant objectively. In the IG, measures are used to generate diabetes risk score.

✓ IG, CG

Routine health check results (medical examination, lab tests, diagnoses) are collected, the questions are derived from a study that was conducted in the same health setting (Esther-Study) [48]. At the last survey, prescription of diabetes medication is asked in addition.

✓ IG, CG