title: Prevalence and risk factors for insomnia among breast cancer patients on aromatase inhibitors.
abstract: OBJECTIVE
  Insomnia is increasingly recognized as a major symptom outcome in breast cancer; however, little is known about its prevalence and risk factors among women receiving aromatase inhibitors (AIs), a standard treatment to increase disease-free survival among breast cancer patients.
  
  
  METHODS
  A cross-sectional survey study was conducted among postmenopausal women with stage 0-III breast cancer receiving adjuvant AI therapy at an outpatient breast oncology clinic of a large university hospital. The insomnia severity index (ISI) was used as the primary outcome. Multivariate logistic regression analyses were performed to evaluate risk factors.
  
  
  RESULTS
  Among 413 participants, 130 (31.5 %) had subthreshold insomnia on the ISI, and 77 (18.64 %) exceeded the threshold for clinically significant insomnia. In a multivariate logistic regression model, clinically significant insomnia was independently associated with severe joint pain (adjusted odds ratio (AOR) 4.84, 95 % confidence interval (CI) 1.71-13.69, P = 0.003), mild/moderate hot flashes (AOR 2.28, 95 % CI 1.13-4.60, P = 0.02), severe hot flashes (AOR 2.29, 95 % CI 1.23-6.81, P = 0.015), anxiety (AOR 1.99, 95 % CI 1.08-3.65, P = 0.027), and depression (AOR 3.57, 95 % CI 1.48-8.52, P = 0.004). Age (>65 vs. <55 years; AOR 2.31; 95 % CI 1.11-4.81; P = 0.026) and time since breast cancer diagnosis (<2 vs. 2-5 years; AOR 1.94; 95 % CI 1.02-3.69; P = 0.045) were also found to be significant risk factors. Clinical insomnia was more common among those who used medication for treating insomnia and pain.
  
  
  CONCLUSIONS
  Insomnia complaints exceed 50 % among AI users. Clinically significant insomnia is highly associated with joint pain, hot flashes, anxiety and depression, age, and time since diagnosis.
authors.affiliation: Department of Family Medicine and Community Health, University of Pennsylvania, 3400 Spruce Street, 2 Gates Building, Philadelphia, PA 19104, USA. krupali.desai@uphs.upenn.edu
authors.forename: Krupali
authors.initials: K
authors.lastname: Desai
authors.forename: Jun J
authors.initials: JJ
authors.lastname: Mao
authors.forename: Irene
authors.initials: I
authors.lastname: Su
authors.forename: Angela
authors.initials: A
authors.lastname: Demichele
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Sharon X
authors.initials: SX
authors.lastname: Xie
authors.forename: Philip R
authors.initials: PR
authors.lastname: Gehrman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000453:epidemiology; D047072:Aromatase Inhibitors / Q000009:adverse effects*; D018771:Arthralgia / Q000453:epidemiology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000453:epidemiology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology; D005260:Female; D019584:Hot Flashes / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D017698:Postmenopause; D015995:Prevalence; D012307:Risk Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000139:chemically induced* / Q000453:epidemiology; D014481:United States / Q000453:epidemiology
chemical_list: D047072:Aromatase Inhibitors