title: Screening and treatment of thyroid dysfunction: an evidence review for the U.S. Preventive Services Task Force.
abstract: BACKGROUND
  In 2004, the U.S. Preventive Services Task Force found insufficient evidence to recommend thyroid screening.
  
  
  OBJECTIVE
  To update the 2004 U.S. Preventive Services Task Force review on the benefits and harms of screening and treatment of subclinical and undiagnosed overt hypothyroidism and hyperthyroidism in adults without goiter or thyroid nodules.
  
  
  METHODS
  MEDLINE and Cochrane databases through July 2014.
  
  
  METHODS
  Randomized, controlled trials and observational studies of screening and treatment.
  
  
  METHODS
  One investigator abstracted data, and a second investigator confirmed; 2 investigators independently assessed study quality.
  
  
  RESULTS
  No study directly assessed benefits and harms of screening versus no screening. For subclinical hypothyroidism (based on thyroid-stimulating hormone levels of 4.1 to 11.0 mIU/L), 1 fair-quality cohort study found that treatment of subclinical hypothyroidism was associated with decreased risk for coronary heart disease events versus no treatment. No study found that treatment was associated with improved quality of life, cognitive function, blood pressure, or body mass index versus no treatment. Effects of treatment versus no treatment showed potential beneficial effects on lipid levels, but effects were inconsistent, not statistically significant in most studies, and of uncertain clinical significance (difference, -0.7 to 0 mmol/L [-28 to 0 mg/dL] for total cholesterol levels and -0.6 to 0.1 mmol/L [-22 to 2 mg/dL] for low-density lipoprotein cholesterol levels). Treatment harms were poorly studied and sparsely reported. Two poor-quality studies evaluated treatment of subclinical hyperthyroidism but examined intermediate outcomes. No study evaluated treatment versus no treatment of screen-detected, undiagnosed overt thyroid dysfunction.
  
  
  CONCLUSIONS
  English-language articles only, no treatment study performed in the United States, and small trials with short duration that used different dosage protocols.
  
  
  CONCLUSIONS
  More research is needed to determine the clinical benefits associated with thyroid screening.
  
  
  BACKGROUND
  Agency for Healthcare Research and Quality.
authors.forename: J Bruin
authors.initials: JB
authors.lastname: Rugge
authors.forename: Christina
authors.initials: C
authors.lastname: Bougatsos
authors.forename: Roger
authors.initials: R
authors.lastname: Chou
mesh_terms: D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000150:complications / Q000401:mortality; D003071:Cognition / Q000187:drug effects; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy*; D007037:Hypothyroidism / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy*; D008403:Mass Screening; D011788:Quality of Life; D018570:Risk Assessment