1. Drugs Aging. 2012 Jul 1;29(7):577-91. doi: 10.2165/11631980-000000000-00000.

Content validity and inter-rater reliability of an instrument to characterize
unintentional medication discrepancies.

Claeys C, Nève J, Tulkens PM, Spinewine A.

Universit libre de Bruxelles, Laboratory of Pharmaceutical Chemistry, Faculty of 
Pharmacy, Brussels, Belgium.

Background: Medication discrepancies are medication-related problems (MRPs) that 
frequently occur when patients are transferred between settings of care. Older
patients are at high risk for several reasons, including high consumption of
medicines, and physical and cognitive deficiencies that can impair the
communication process. Most previous studies that have evaluated medication
discrepancies used instruments designed for clinical practice, but a
well-validated and reliable instrument for clinical research is still lacking.
Objectives: The aims of this study were to (i) develop an instrument to
characterize medication discrepancies that fulfils quality requirements for
classification of MRPs related to continuity of care and (ii) assess its content 
validity and inter-rater reliability. Methods: The instrument was developed based
on three main inputs: (i) a literature review to collect information about the
quality requirements of instruments to characterize MRPs; (ii) another literature
review to identify existing instruments to characterize MRPs and, more
specifically, medication discrepancies; and (iii) previous experience from a
pilot study on Belgian patients discharged from surgical and medical wards.
Content validity was assessed using a modified Delphi technique with 11
healthcare professionals. Content validity indexes were calculated. For
inter-rater reliability, three pharmacists (one experienced and two naive) were
asked to identify and categorize (type and cause of) unintentional medication
discrepancies for 21 patients discharged from hospital into the community. The
intra-class correlation coefficient was calculated to compare the number of
discrepancies identified, and a paradox-resistant index (AC1) was used to
determine the inter-rater reliability for the type and cause of the discrepancy. 
Results: The instrument had 54 items classified in three sections (type of
discrepancy, cause and intervention), with detailed specifications on how to use 
it. All evaluations relative to content validity met predefined cut-off values,
except for two of them. Intra-class correlation coefficients of ≥0.76 and AC1
coefficients of ≥0.89 were found for the number and the type of discrepancies,
respectively. Regarding evaluation of the specific causes of medication
discrepancies, final AC1 results of ≥0.86 were obtained, except for three items
(which had values between 0.62 and 0.79). Conclusion: The validity and
reliability of the instrument developed to assess unintentional medication
discrepancies at patient transition from the hospital to the community setting
was found to be satisfactory.

PMID: 22715864  [PubMed - in process]