title: Validation of a simplified medication adherence questionnaire in a large cohort of HIV-infected patients: the GEEMA Study.
abstract: OBJECTIVE
  To assess the effectiveness of the simplified medication adherence questionnaire (SMAQ) in identifying non-adherent patients.
  
  
  METHODS
  Prospective observational study of adherence. The six-item SMAQ was developed. The following aspects were evaluated: (i) criterion validity, comparison with electronic adherence monitoring; (ii) construct validity, association between adherence, as defined by the SMAQ, and virological outcomes; and (iii) reliability, internal consistency and reproducibility.
  
  
  METHODS
  A group of 3004 unselected HIV patients who had initiated nelfinavir therapy combined with other antiretroviral drugs [21% naive, 15% protease inhibitor (PI)-naive, 64% PI-experienced] between January 1998 and December 1999 were enrolled in 69 hospitals in Spain. The SMAQ was administered at months 3, 6 and 12.
  
  
  RESULTS
  The SMAQ showed 72% sensitivity, 91% specificity and a likelihood ratio of 7.94 to identified non-adherent patients, compared with the medication-event monitoring system (40 patients evaluated). At month 12, 1797 patients were evaluated, of whom 32.3% were defined as non-adherent; viral load < 500 copies/ml found in 68.3% of the adherent, and 46% of the non-adherent patients. A logistic regression analysis of PI-naive patients was performed, including age, sex, baseline viral load > 5 log10/ml, CD4 cell count < 200 x 10(6)/l, and non-adherence as independent variables. Non-adherence was the only significant risk factor in failing to achieve virological suppression. Cronbach's alpha internal consistency coefficient was 0.75, and overall inter-observer agreement was 88.2%.
  
  
  CONCLUSIONS
  The SMAQ appears to be an adequate instrument with which to assess adherence in HIV-infected patients, and may be applied in most clinical settings.
authors.affiliation: Department of Internal Medicine-Infectious Diseases, Hospital del Mar, Paseo Marítimo 25-29, 08003 Barcelona, Spain. hknobel@imas.imem.es
authors.forename: Hernando
authors.initials: H
authors.lastname: Knobel
authors.forename: Jordi
authors.initials: J
authors.lastname: Alonso
authors.forename: José L
authors.initials: JL
authors.lastname: Casado
authors.forename: Julio
authors.initials: J
authors.lastname: Collazos
authors.forename: Juan
authors.initials: J
authors.lastname: González
authors.forename: Isabel
authors.initials: I
authors.lastname: Ruiz
authors.forename: José M
authors.initials: JM
authors.lastname: Kindelan
authors.forename: Alexia
authors.initials: A
authors.lastname: Carmona
authors.forename: Javier
authors.initials: J
authors.lastname: Juega
authors.forename: Antonio
authors.initials: A
authors.lastname: Ocampo
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology / Q000523:psychology* / Q000821:virology; D017320:HIV Protease Inhibitors / Q000627:therapeutic use; D006801:Humans; D008297:Male; D010349:Patient Compliance / Q000706:statistics & numerical data*; D011446:Prospective Studies; D013030:Spain; D011795:Surveys and Questionnaires / Q000592:standards*; D016896:Treatment Outcome
chemical_list: D017320:HIV Protease Inhibitors