Table 1

Measurement of case-mix variables used in this study
Variables Measurement Used in analyses as
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.

a These categories were used as reference group.

Tol et al.

Tol et al. BMC Health Services Research 2012 12:317   doi:10.1186/1472-6963-12-317

Open Data