title: International variation in GP treatment strategies for subclinical hypothyroidism in older adults: a case-based survey.
abstract: BACKGROUND
  There is limited evidence about the impact of treatment for subclinical hypothyroidism, especially among older people.
  
  
  OBJECTIVE
  To investigate the variation in GP treatment strategies for older patients with subclinical hypothyroidism depending on country and patient characteristics.
  
  
  METHODS
  Case-based survey of GPs in the Netherlands, Germany, England, Ireland, Switzerland, and New Zealand.
  
  
  METHODS
  The treatment strategy of GPs (treatment yes/no, starting-dose thyroxine) was assessed for eight cases presenting a woman with subclinical hypothyroidism. The cases differed in the patient characteristics of age (70 versus 85 years), vitality status (vital versus vulnerable), and thyroid-stimulating hormone (TSH) concentration (6 versus 15 mU/L).
  
  
  RESULTS
  A total of 526 GPs participated (the Netherlands n = 129, Germany n = 61, England n = 22, Ireland n = 21, Switzerland n = 262, New Zealand n = 31; overall response 19%). Across countries, differences in treatment strategy were observed. GPs from the Netherlands (mean treatment percentage 34%), England (40%), and New Zealand (39%) were less inclined to start treatment than GPs in Germany (73%), Ireland (62%), and Switzerland (52%) (P = 0.05). Overall, GPs were less inclined to start treatment in 85-year-old than in 70-year-old females (pooled odds ratio [OR] 0.74 [95% confidence interval [CI] = 0.63 to 0.87]). Females with a TSH of 15 mU/L were more likely to get treated than those with a TSH of 6 mU/L (pooled OR 9.49 [95% CI = 5.81 to 15.5]).
  
  
  CONCLUSIONS
  GP treatment strategies of older people with subclinical hypothyroidism vary largely by country and patient characteristics. This variation underlines the need for a new generation of international guidelines based on the outcomes of randomised clinical trials set within primary care.
authors.affiliation: Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Wendy P J
authors.initials: WP
authors.lastname: den Elzen
authors.affiliation: Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Anne A
authors.initials: AA
authors.lastname: Lefèbre-van de Fliert
authors.affiliation: Department of General Internal Medicine, Inselspital, University of Bern, Bern, Switzerland.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Virgini
authors.affiliation: Institute for Evidence-Based Medicine in Old Age (IEMO), Leiden, the Netherlands, and Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Mooijaart
authors.affiliation: Bern Institute of General Practice, University of Bern, Bern, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Frey
authors.affiliation: Department of Epidemiology and Public Health, University College Cork, Cork, Ireland.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Kearney
authors.affiliation: Department of General Practice and Primary Health Care, University of Auckland, Auckland, New Zealand.
authors.forename: Ngaire
authors.initials: N
authors.lastname: Kerse
authors.affiliation: Arthritis Research UK Primary Care Centre, Keele University, Keele, Staffordshire, UK.
authors.forename: Christian D
authors.initials: CD
authors.lastname: Mallen
authors.affiliation: Department of Epidemiology and Public Health, University College Cork, Cork, Ireland.
authors.forename: Vera J C
authors.initials: VJ
authors.lastname: McCarthy
authors.affiliation: Institute of General Practice, Johann Wolfgang Goethe University, Frankfurt, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Muth
authors.affiliation: Institute of General Practice and Health Services Research, University of Zürich, Zürich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rosemann
authors.affiliation: Department of Epidemiology and Public Health, University College Cork, Cork, Ireland.
authors.forename: Audrey
authors.initials: A
authors.lastname: Russell
authors.affiliation: Department of Primary and Community Care, Radboud University Medical Center Nijmegen, Nijmegen, the Netherlands.
authors.forename: Henk
authors.initials: H
authors.lastname: Schers
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Scotland, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Stott
authors.affiliation: Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Margot W M
authors.initials: MW
authors.lastname: de Waal
authors.affiliation: Research Department of Primary Care and Population Health, University College London, UK.
authors.forename: Alex
authors.initials: A
authors.lastname: Warner
authors.affiliation: Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, the Netherlands, and Leyden Academy on Vitality and Ageing, Leiden, the Netherlands.
authors.forename: Rudi G J
authors.initials: RG
authors.lastname: Westendorp
authors.affiliation: Department of General Internal Medicine, Inselspital, University of Bern, Bern, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rodondi
authors.affiliation: Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Jacobijn
authors.initials: J
authors.lastname: Gussekloo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy*; D008297:Male; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians' / Q000592:standards*; D011795:Surveys and Questionnaires; D013972:Thyrotropin / Q000627:therapeutic use*
chemical_list: D013972:Thyrotropin
keywords: general practice; subclinical hypothyroidism; survey