Objective Evaluate the internal consistency and temporal stability of advance directives (ADs) generated by an interactive, online computer program.
Methods 33 participants completed the program at three visits, 2 weeks apart. Agreement rates were calculated for the General Wishes component of the AD. The test–retest method was used to examine the temporal stability of the Specific Wish for Treatment component which contains five clinical scenarios.
Results General Wishes remained stable with 94% selecting the identical response at each visit. For the Specific Wish for Treatment scale, significant variations in test–retest correlations existed (ie, ρ=0.32–0.78, between time points 1 and 2); however within scenario, correlations did not significantly vary between time points. Temporal stability was lower in the Specific Wish for Treatment scale compared with General Wishes (average ρ=0.59, between time points 1 and 2; and ρ=0.75, between time points 2 and 3).
Conclusions ADs generated by an online decision aid demonstrate good temporal stability, with highest stability for General Wishes and moderate stability for Specific Wish for Treatment regarding medical treatments in specific clinical scenarios. Internal consistency for wish for treatment across all time points and scenarios was high (Cronbach α>0.90).
- Supportive care
- Received 3 November 2014.
- Revision received 7 January 2015.
- Accepted 17 February 2015.
- Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
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Funding This study was funded by grants from the National Institute of Nursing Research (R21NR008539), and Penn State University (Social Science Research Institute, Woodward Endowment for Medical Science Education, and Tobacco Settlement Fund Award).
Competing interests MJG and BHL have intellectual property and copyright interests for the decision aid used for this study, Making Your Wishes Known: Planning Your Medical Future (MYWK), which could result in future royalties or income to them.
Patient consent Obtained.
Ethics approval This study was approved by the Penn State College of Medicine's Institutional Review Board before the study began.
Provenance and peer review Not commissioned; externally peer reviewed.
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