The TLM consists of two parts: (I) a lifestyle behaviour screening followed by creating a lifestyle plan and (II) a follow-up phase. In the lifestyle behaviour screening, the patient, together with a nurse, answers questions on several health and lifestyle related domains, see Table 2 for an overview of these domains. The Traffic Light Method displays a risk profile with all lifestyle behaviours in green, orange or red, depending on the level of risk. The patient creates, while being coached by the nurse, a lifestyle plan containing maximum three attainable lifestyle goals. During the subsequent follow-up phase, nurse and patient will systematically evaluate the patient’s progress in achieving the lifestyle goals described in the lifestyle plan. This will be done biweekly during regular care visits for approximately 15 min. In order to enhance and stimulate behaviour change, several techniques are built in the web tool. The aims of the lifestyle behaviour screening and the follow-up phase are presented in Table 3.Table 2Domains and subdomains in web tool Traffic Light Method (TLM)DomainSubdomains(a) General medical information1. Physical measuresa 2. Measures from lab testa 3. Physical diseases and handicaps4. Rating own health(b) Use of medication1. Satisfaction with medication use2. Somatic medication3. Psychiatric medication4. Freely available medication(c) Dietary habits (last 7 days)1. Satisfaction with own dietary behaviour2. Rating own dietary behaviour3. Assessing stage-of-change for dietary behaviour change4. Assessing dietary habits(d) Physical activity (last month)1. Satisfaction with own physical activity2. Rating own physical activity3. Assessing physical activity with SQUASH questionnaire4. Assessing stage-of-change for physical activity behaviour change5. Sedentary behaviour(e) Use of stimulants1. Disadvantages of dependence on substances2. History of substance abuse3. Use of alcohol4. Smoking behaviour(f) Other lifestyle factors1. Personal hygiene2. Relaxation3. Sleep behaviour4. Computer behaviour5. Social environment(g) Sexuality1. Condom use2. Sexually transmitted diseases(h) Lifestyle planb a Measures are taken from the Routine Outcome Monitoring screening conducted within two months prior to the web tool assessment. b Only available for participants in the intervention group Table 3Aims for the lifestyle behaviour screening and the follow-up phase in the lifestyle interventionAimDescription of aim per phaseLifestyle behaviour screening phase1Identify unhealthy lifestyle behaviours. The tool uses a traffic light principle for a clear visible presentation of possible health risks related to certain lifestyle behaviours, with green colours representing behaviours with low or no health related risk and red colours representing behaviours with high health related risks (see Fig. 2b).2Increase patient’s and nurse’s knowledge of healthy lifestyle behaviours. The tool provides direct feedback on what healthy behaviours are according to (inter)national guidelines and gives additional information to increase patient’s and nurse’s knowledge on healthy lifestyle behaviours (see Fig. 2b).3Create awareness. Patients are challenged to discuss identified risk factors and nurses support patients in deciding what lifestyle behaviours to change. Nurses use MI and stages-of-change techniques to assist patients in identifying their problems and overcoming ambivalence or resistance to behaviour change. It is supported by regularly classifying the patient’s current stage-of-change.4Create a lifestyle plan with concrete and reachable goals. Based on the lifestyle anamnesis and discussion with the nurse, patients set maximum three goals to achieve according to the criteria of S.M.A.R.T.-goals . The nurse’s role is to support patients in setting realistic goals. Patients explore which interventions are available and seem attractive, and what is needed to reach goals. Active self-management of patients is encouraged, support of family and friends is explored and, when available and deemed necessary, incorporated in the plan.Follow-up phase6Evaluating lifestyle goals systematically on a regular basis. During every regular care visit, a new follow-up file is uploaded and filled in by patient and nurse. By doing this, continuity is ensured and this repetitive character will lead to more sustainable behaviour change.7Barriers and facilitators in achieving lifestyle goals are indicated. Patient and nurse discuss which factors are helpful in achieving goals and which factors limit achieving goals in order to increase the success of achieving the goals in the following period. Again, nurses use motivational interviewing techniques and the stages-of-change of the transtheoretical model.