title: Home Circadian Phase Assessments with Measures of Compliance Yield Accurate Dim Light Melatonin Onsets.
abstract: OBJECTIVE
  There is a need for the accurate assessment of circadian phase outside of the clinic/laboratory, particularly with the gold standard dim light melatonin onset (DLMO). We tested a novel kit designed to assist in saliva sampling at home for later determination of the DLMO. The home kit includes objective measures of compliance to the requirements for dim light and half-hourly saliva sampling.
  
  
  METHODS
  Participants were randomized to one of two 10-day protocols. Each protocol consisted of two back-to-back home and laboratory phase assessments in counterbalanced order, separated by a 5-day break.
  
  
  METHODS
  Laboratory or participants' homes.
  
  
  METHODS
  Thirty-five healthy adults, age 21-62 y.
  
  
  METHODS
  N/A.
  
  
  RESULTS
  Most participants received at least one 30-sec epoch of light > 50 lux during the home phase assessments (average light intensity 4.5 lux), but on average for < 9 min of the required 8.5 h. Most participants collected every saliva sample within 5 min of the scheduled time. Ninety-two percent of home DLMOs were not affected by light > 50 lux or sampling errors. There was no significant difference between the home and laboratory DLMOs (P > 0.05); on average the home DLMOs occurred 9.6 min before the laboratory DLMOs. The home DLMOs were highly correlated with the laboratory DLMOs (r = 0.91, P < 0.001).
  
  
  CONCLUSIONS
  Participants were reasonably compliant to the home phase assessment procedures. The good agreement between the home and laboratory dim light melatonin onsets (DLMOs) demonstrates that including objective measures of light exposure and sample timing during home saliva sampling can lead to accurate home DLMOs.
  
  
  BACKGROUND
  Circadian Phase Assessments at Home, http://clinicaltrials.gov/show/NCT01487252, NCT01487252.
authors.affiliation: Biological Rhythms Research Laboratory, Department of Behavioral Sciences, Rush University Medical Center, Chicago, IL.
authors.forename: Helen J
authors.initials: HJ
authors.lastname: Burgess
authors.affiliation: Sleep Disorders Service and Research Center, Department of Behavioral Sciences, Rush University Medical Center, Chicago, IL.
authors.forename: James K
authors.initials: JK
authors.lastname: Wyatt
authors.affiliation: Sleep Disorders Service and Research Center, Department of Behavioral Sciences, Rush University Medical Center, Chicago, IL.
authors.forename: Margaret
authors.initials: M
authors.lastname: Park
authors.affiliation: College of Nursing, Rush University Medical Center, Chicago, IL.
authors.forename: Louis F
authors.initials: LF
authors.lastname: Fogg
mesh_terms: D000328:Adult; D002940:Circadian Rhythm / Q000528:radiation effects*; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008550:Melatonin / Q000032:analysis / Q000378:metabolism*; D008875:Middle Aged; D010349:Patient Compliance; D011897:Random Allocation; D012463:Saliva / Q000737:chemistry / Q000378:metabolism; D013048:Specimen Handling
chemical_list: D008550:Melatonin
keywords: circadian; compliance; light; melatonin