Development and Validation of the self-Rated Health and Self-Medication Questionnaire for Adults in Greece

Velissari Joanna, Ioanna Chatziprodromidou, Maria Psilopoulou and Apostolos Vantarakis

Published on: 2023-01-17

Abstract

The aim of this study was to develop and validate a novel, self-administered questionnaire to identify the general population’s knowledge and attitudes regarding self-rated health (SRH) and self-medication (SM).This investigation was embedded within a one-year randomized cohort study, about SRH and SMpractice amongthe general adult populationand their children, if they were parents.The study was conducted in five steps. Step Iconsisted of a review and qualitative study, in which items were formulated and the questionnaire was designed; in Step II content validation was performed; inStep III face validity was evaluated by a panel of experts, who reformulated, added, and deleted items and conducted a pilot study on a population with similar characteristics; in Step IV the overall reliability and accessibility of the questionnaire was analyzed by means of a test retest study. To determine SM and SRH content validity, we assessed the Item Content Validity Index and Kappa and to determinereliability we usedtest-retest reliability as well as Cronbach’s α coefficients.The Item Content Validity Index (I-CVI) and modified Kappa statistic (K*), confirmed the content validity of the questions (0.78 ≤ I-CVI ≤ 1.00 and 0.78 ≤ K* ≤ 1.00). The I-CVI values for SRH and SM was 0.9, Kappa was 0.8 and and Cronbach’s α (internal consistency) values were 0.81 and 0.82. The S-CVI statistic showed the content validity of the scale (S-CVI/Ave: 0.95).Following Steps, I and II, the questionnaire contained 85 items. Participants inthe pilot study (Step III) reported no difficulty. Following face validity and pilot testing, the Test–Retest Reliability in a sample of 135 adults confirmed the reliability of the questions. The test–retest study (Step IV) showed that initialknowledge and attitude items yielded an ICC of 0.5. The final version of the fully validated questionnaire could prove useful for research as it permits generating high quality data and reducing measurement error.The final SRH and SM questionnaire appears to be valid, reliable and responsive.