Examining assumptions regarding valid electronic monitoring of medication therapy: development of a validation framework and its application on a European sample of kidney transplant patients

BACKGROUND: Electronic monitoring (EM) is used increasingly to measure medication non-adherence. Unbiased EM assessment requires fulfillment of assumptions. The purpose of this study was to determine assumptions needed for internal and external validity of EM measurement. To test internal validity, we examined if (1) EM equipment functioned correctly, (2) if all EM bottle openings corresponded to actual drug intake, and (3) if EM did not influence a patient's normal adherence behavior. To assess external validity, we examined if there were indications that using EM affected the sample representativeness. METHODS: We used data from the Supporting Medication Adherence in Renal Transplantation (SMART) study, which included 250 adult renal transplant patients whose adherence to immunosuppressive drugs was measured during 3 months with the Medication Event Monitoring System (MEMS). Internal validity was determined by assessing the prevalence of nonfunctioning EM systems, the prevalence of patient-reported discrepancies between cap openings and actual intakes (using contemporaneous notes and interview at the end of the study), and by exploring whether adherence was initially uncharacteristically high and decreased over time (an indication of a possible EM intervention effect). Sample representativeness was examined by screening for differences between participants and non-participants or drop outs on non-adherence. RESULTS: Our analysis revealed that some assumptions were not fulfilled: 1) one cap malfunctioned (0.4%), 2) self-reported mismatches between bottle openings and actual drug intake occurred in 62% of the patients (n = 155), and 3) adherence decreased over the first 5 weeks of the monitoring, indicating that EM had a waning intervention effect. CONCLUSION: The validity assumptions presented in this article should be checked in future studies using EM as a measure of medication non-adherence

Psychometric testing of the consequences of an HIV disclosure instrument in Mandarin: a cross-sectional study of persons living with HIV in Hunan, China

Xueling Xiao,1 Junshi Zhao,2 Chulei Tang,1 Xianhong Li,1 Jane M Simoni,3 Honghong Wang,1 Kristopher P Fennie4 1Xiangya School of Nursing, Central South University, Changsha, People’s Republic of China; 2Department of STD/AIDS, Center for Disease Control and Prevention of Hunan Province, Changsha, People’s Republic of China; 3Department of Psychology, University of Washington, Seattle, WA, USA; 4Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, USA Purpose: This study aimed to examine the psychometric properties of a Mandarin-language version of an instrument that assesses the Consequences of HIV Disclosure (CoHD).Patients and methods: The original CoHD instrument developed by Serovich was translated into Mandarin and administered to a random sample of 184 persons living with HIV (PLWH) using face-to-face and structured interviews. The CoHD instrument required respondents to rate the importance of eight costs (eg, might lose the relationship) and ten rewards (eg, would bring us closer) in their decision about whether to self-disclose their HIV status. The participants were directed to respond with respect to a current (or hypothetical) sexual partner.Results: Internal consistency was acceptable (Cronbach’s α for the overall scale 0.82, costs 0.71, and rewards 0.86), as was stability (test–retest reliability overall 0.74, cost 0.63, and rewards 0.82). The CVI for the scale was 0.83, with items rated by subject experts ranging from 0.80 to 1.0. To determine structural validity, exploratory factor analysis extracted two subscales consistent with the original CoHD subscales. The Mandarin CoHD scores were significantly correlated with disclosure self-efficacy (indicating convergent validity), but they were unrelated to safer sex efficacy (indicating divergent validity). This criterion was tested by comparing the scores of PLWH who disclosed their HIV status (mean±SD 53.57±9.06) with those who did not disclose it (mean±SD 49.63±7.45); however, the difference was not statistically significant.Conclusion: The Mandarin version of the CoHD instrument demonstrates promising psychometric properties when assessing costs and rewards with respect to sexual partner disclosure. This suggests that it might be useful in research on partner notification strategies. In further studies, larger and more diverse samples and an analysis of responses for different disclosure targets are warranted. Moreover, whether the CoHD score is related to the decision of disclosure should be determined. Keywords: HIV, self-disclosure, sexual partner, partner notification, psychometric analysis, Chin