Table 1 Measurement of case-mix variables used in this study

Patients’ demographics (model 1)

Gender

Categorical: Male ^a; Female

Age

Date of birth

Continuous: years of age at start of the treatment.

Ethnicity

Patient’s origin

Categorical: Immigrant ^a, from a non-western country, i.e. Turkey, Africa, Latin-America and Asia; Native Dutch, including western immigrants originally from Europe, North-America, Oceania, Indonesia, Japan.

Educational level

Highest level of education

Categorical: Low (Primary school) ^a; Medium (Secondary- or higher education); High (University); Other (not specified, e.g. in children).

Urbanicity

Zip-code of the address

Categorical: High (≥ 1500 addresses per km²); Medium (1000–1499 addresses per km²); Low (< 999 addresses per km²).

History in Dietetics

The patient had previous dietetic health care in the past 5 years.

Categorical: No ^a; Yes.

Patients’ initiative (model 2)

Initiative treatment

The patient was referred to the dietitian initiated by the referrer or the patient.

Categorical: Referrer ^a; Patient.

Patients’ health (model 3)

Communication problem

According to the dietitian

Categorical: No ^a, Yes.

Psychiatric problem

According to the dietitian

Categorical: No ^a, Yes.

Intellectual disability problem

According to the dietitian

Categorical: No ^a, Yes.

Multiple diagnoses

Number of diagnoses per patient (max. 4)

Categorical: Single diagnosis ^a, multiple diagnosis

Overweight

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Underweight/unwanted weight loss

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Hypercholesterolemia

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Diabetes

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Food intolerance

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Irritable Bowel Syndrome

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Binge eating disorder

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Overweight & Diabetes;

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Overweight & Hypertension

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Overweight & Hypercholesterolemia;

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Overweight & Diabetes & Hypercholesterolemia;

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Overweight & Diabetes & Hypertension;

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Overweight & Binge eating disorder;

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Overweight & Irritable Bowel Syndrome

Type of diagnosis according to the dietitian

Categorical: No ^a; Yes.

Therapists’ demographics (model 4)

Gender

Categorical: Male ^a; Female

Age

Date of birth

Continuous: years of age at start of the study.