Predictive validity of the Sidorkiewicz instrument in Spanish: Assessing individual drug adherence in psychiatric patients

Abstract

Background/Objective: Concomitant prescription of two or more psychiatric medications has become the rule and patients could adhere differently to their various drugs prescribed. Sidorkiewicz et al. published a questionnaire for assessing adherence to each specific drug. Method: This study explored the predictive validity of the Spanish version of the Sidorkiewicz questionnaire in a sample of 470 consecutive psychiatric outpatients using 897 psychiatric drugs. Results: The questionnaire showed adequate predictive validity in both univariate and multivariate analyses (logistic regression and CHAID segmentation) since they demonstrated a significant association with the 10-item Drug Attitude Inventory and with the Necessity and Concern Scales of the Beliefs about Medications Questionnaire. Some demographic and clinical variables were significant in the univariate analyses but lost significance in the multivariate analyses. Conclusions: The adherence of the psychiatric patient to his/her prescribed treatment may not be significantly influenced by socio-demographic or clinical characteristics, but rather by attitudes toward medication, perceptions of personal necessity for medication, and concerns about its potential adverse effects. This study's findings suggest that the Spanish version of the Sidorkiewicz questionnaire may be a useful and valid instrument for assessing adherence to each individual drug taken by psychiatric outpatients undergoing polypsychopharmacy.

The necessity‐concern framework in the assessment of treatment adherence of psychiatric patients and the role of polypharmacy in a Spanish sample

“…The necessity and concerns scales are usually split at the median to generate four attitudinal groups: accepting (high necessity and low concern), ambivalent (high necessity and high concern), indifferent (low necessity and low concern), and skeptical (low necessity and high concern). The skeptical attitude group is the one that is associated with decreased adherence (De las Cuevas et al, , b).…”

“…The necessity‐concern framework has proven to be a useful conceptual model for understanding patients' perspectives on prescribed medicines and is a strong predictor of health beliefs, stronger than sociodemographic variables (Foot, La Caze, Gujral, & Cottrell, ; Horne et al, , ; Horne & Weinman, ). Four methods of measuring this framework have been used: (a) necessity and concern scored as separate predictors (Horne et al, ; Horne et al, ; O'Carroll et al, ); (b) the necessity‐concern differential (Foot et al, ; Horne et al, ; Horne & Weinman, ); (c) the four patient attitudes of skepticism, ambivalence, indifference, and acceptance (Aikens et al, ; De las Cuevas, Peñate, et al, ); and (d) a multidimensional model using polynomial regression (Phillips, Diefenbach, Kronish, Negron, & Horowitz, ).…”

Skepticism and pharmacophobia toward medication may negatively impact adherence to psychiatric medications: a comparison among outpatient samples recruited in Spain, Argentina, and Venezuela

“…Medication adherence was assessed using the Spanish version of the validated Sidorkiewicz instrument to assess treatment adherence for each individual drug taken by a patient. 22 , 23 This instrument contains five questions with two or three possible answers, illustrated with practical examples and pictographs, to help patients recognize their different medication-taking behaviors for each drug taken. The major advantage of the Sidorkiewicz tool is allowing clinicians to identify how patients adhere to drugs during polypharmacy.…”

<p>Effectiveness and cost-effectiveness of a multicomponent intervention to improve medication adherence in people with depressive disorders - MAPDep: a study protocol for a cluster randomized controlled trial</p>

“…The primary end point is rate of adherence to the antidepressant drug at 6 months assessed using the Sidorkiewicz adherence instrument in Spanish. 74,75 This is a five-item instrument with two or three possible answers to assess different medication-taking behaviors for each individual drug taken by patients. The results generate adherence levels ranging from 1 (high drug adherence) to 6 (drug discontinuation).…”