title: Treatment adherence and health outcomes in patients with bronchiectasis.
abstract: BACKGROUND
  We aimed to determine adherence to inhaled antibiotics, other respiratory medicines and airway clearance and to determine the association between adherence to these treatments and health outcomes (pulmonary exacerbations, lung function and Quality of Life Questionnaire-Bronchiectasis [QOL-B]) in bronchiectasis after 12 months.
  
  
  METHODS
  Patients with bronchiectasis prescribed inhaled antibiotics for Pseudomonas aeruginosa infection were recruited into a one-year study. Participants were categorised as "adherent" to medication (medication possession ratio ≥80% using prescription data) or airway clearance (score ≥80% in the Modified Self-Reported Medication-Taking Scale). Pulmonary exacerbations were defined as treatment with a new course of oral or intravenous antibiotics over the one-year study. Spirometry and QOL-B were completed at baseline and 12 months. Associations between adherence to treatment and pulmonary exacerbations, lung function and QOL-B were determined by regression analyses.
  
  
  RESULTS
  Seventy-five participants were recruited. Thirty-five (53%), 39 (53%) and 31 (41%) participants were adherent to inhaled antibiotics, other respiratory medicines, and airway clearance, respectively. Twelve (16%) participants were adherent to all treatments. Participants who were adherent to inhaled antibiotics had significantly fewer exacerbations compared to non-adherent participants (2.6 vs 4, p = 0.00) and adherence to inhaled antibiotics was independently associated with having fewer pulmonary exacerbations (regression co-efficient = -0.51, 95% CI [-0.81,-0.21], p < 0.001). Adherence to airway clearance was associated with lower QOL-B Treatment Burden (regression co-efficient = -15.46, 95% CI [-26.54, -4.37], p < 0.01) and Respiratory Symptoms domain scores (regression co-efficient = -10.77, 95% CI [-21.45; -0.09], p < 0.05). There were no associations between adherence to other respiratory medicines and any of the outcomes tested. Adherence to treatment was not associated with FEV1 % predicted.
  
  
  CONCLUSIONS
  Treatment adherence is low in bronchiectasis and affects important health outcomes including pulmonary exacerbations. Adherence should be measured as part of bronchiectasis management and future research should evaluate bronchiectasis-specific adherence strategies.
authors: Amanda R
authors: AR
authors: McCullough
authors: Michael M
authors: MM
authors: Tunney
authors: Alexandra L
authors: AL
authors: Quittner
authors: J Stuart
authors: JS
authors: Elborn
authors: Judy M
authors: JM
authors: Bradley
authors: Clinical & Practice Research Group, School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK. c.hughes@qub.ac.uk.
authors: Carmel M
authors: CM
authors: Hughes
mesh_terms: D000280:Administration, Inhalation; D000284:Administration, Oral; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001987:Bronchiectasis / Q000175:diagnosis / Q000382:microbiology / Q000628:therapy*; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data*; D016012:Poisson Distribution; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000175:diagnosis / Q000188:drug therapy*; D011788:Quality of Life; D012138:Respiratory Therapy / Q000379:methods*; D018570:Risk Assessment; D012720:Severity of Illness Index; D013256:Steroids / Q000627:therapeutic use; D016896:Treatment Outcome; D016903:Drug Monitoring
chemical_list: D000900:Anti-Bacterial Agents; D013256:Steroids