title: Temporal and regional variability in the request of vitamin D from general practitioners in Spain.
abstract: BACKGROUND
  Our main goal is to study the inter-practice regional variability and the temporal evolution in the request of 25-hydroxyvitamin D (25[OH]D) by general practitioners (GPs) in Spain.
  
  
  METHODS
  Clinical laboratories in different autonomic communities (AACCs) were invited to report the number of 25(OH)D test requested by GPs during 2012 and 2014. The number of 25(OH)D requested per 1000 inhabitants and the index of variability were calculated, and compared between regions and time periods. We calculated the number of tests that could have been potentially saved in regions where 25(OH)D could be requested from primary care without restrictions taking into account the request in those where it is restricted, and the potential economical savings.
  
  
  RESULTS
  Seventy-six laboratories participated in the 2012 edition, and 110 in 2014, corresponding to 17,679,195 and 27,798,262 inhabitants (59.8% Spanish population). The number of 25(OH)D requested per 1000 inhabitants increased from 1.1 in 2012 to 3.4 in 2014 (p<0.001). The variability index also increased from 51.7 to 68. There was a significantly variability among the different AACCs, ranging from 0.94 to 21.24 (p=0.002). 173,885 tests could have been not measured from primary care in regions without ordering restrictions, resulting in potential 886,813.5€ savings.
  
  
  CONCLUSIONS
  There was a high variability in the request of 25(OH)D by GPs in Spain, which significantly increased in a 2 year period. The demand was higher in areas where the request of 25(OH)D was not restricted in primary care, with potential savings if the request would approach to regions with ordering restrictions.
authors.affiliation: .
authors.forename: Maria
authors.initials: M
authors.lastname: Salinas
authors.affiliation: .
authors.forename: Maite
authors.initials: M
authors.lastname: López-Garrigós
authors.affiliation: .
authors.forename: Emilio
authors.initials: E
authors.lastname: Flores
authors.affiliation: .
authors.forename: Carlos
authors.initials: C
authors.lastname: Leiva-Salinas
mesh_terms: D064790:Clinical Laboratory Services; D034742:Electronic Mail; D058005:General Practitioners / Q000523:psychology; D006801:Humans; D010818:Practice Patterns, Physicians' / Q000191:economics*; D011320:Primary Health Care; D013030:Spain; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood / Q000191:economics
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: appropriateness; demand management; primary care; vitamin D