title: Factors associated with the number of consultations per dietetic treatment: an observational study.
abstract: BACKGROUND
  Greater understanding of the variance in the number of consultations per dietetic treatment will increase the transparency of dietetic healthcare. Substantial inter-practitioner variation may suggest a potential to increase efficiency and improve quality. It is not known whether inter-practitioner variation also exists in the field of dietetics. Therefore, the aims of this study are to examine inter-practitioner variation in the number of consultations per treatment and the case-mix factors that explain this variation.
  
  
  METHODS
  For this observational study, data were used from the National Information Service for Allied Health Care (LiPZ). LiPZ is a Dutch registration network of allied health care professionals, including dietitians working in primary healthcare. Data were used from 6,496 patients who underwent dietetic treatment between 2006 and 2009, treated by 27 dietitians working in solo practices located throughout the Netherlands. Data collection was based on the long-term computerized registration of healthcare-related information on patients, reimbursement, treatment and health problems, using a regular software program for reimbursement. Poisson multilevel regression analyses were used to model the number of consultations and to account for the clustered structure of the data.
  
  
  RESULTS
  After adjusting for case-mix, seven percent of the total variation in consultation sessions was due to dietitians. The mean number of consultations per treatment was 4.9 and ranged from 2.3-10.1 between dietitians. Demographic characteristics, patients' initiative and patients' health problems explained 28% of the inter-practitioner variation. Certain groups of patients used significantly more dietetic healthcare compared to others, i.e. older patients, females, the native Dutch, patients with a history of dietetic healthcare, patients who started the treatment on their own initiative, patients with multiple diagnoses, overweight, or binge eating disorder.
  
  
  CONCLUSIONS
  Considerable variation in number of consultations per dietetic treatment is due to dietitians. Some of this inter-practitioner variation was reduced after adjusting for case-mix. Further research is necessary to study the relation between inter-practitioner variation and the effectiveness and quality of dietetic treatment.
authors.affiliation: NIVEL, Netherlands Institute for Health Services Research, Utrecht, The Netherlands. J.Tol@nivel.nl
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Tol
authors.forename: Ilse C
authors.initials: IC
authors.lastname: Swinkels
authors.forename: Peter M
authors.initials: PM
authors.lastname: Spreeuwenberg
authors.forename: Chantal J
authors.initials: CJ
authors.lastname: Leemrijse
authors.forename: Dinny H
authors.initials: DH
authors.lastname: de Bakker
authors.forename: Cindy
authors.initials: C
authors.lastname: Veenhof
mesh_terms: D000328:Adult; D003710:Demography; D004046:Dietetics / Q000592:standards*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009426:Netherlands; D019370:Observation; D016012:Poisson Distribution; D012017:Referral and Consultation / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires