Construct | Measure | Number of items | English reliability/validity | Spanish reliability/validity | Screener | Baseline | 1 week | 3 months | 6 months | 12 months |
---|---|---|---|---|---|---|---|---|---|---|
Eligibility screening | ||||||||||
Cognitive impairment | SPMSQ 0–2=eligible 3–7 moderate impairment → Mini-Cog ≥8 severe impairment=ineligible | 7 | Sensitivity 86.2%, specificity 99.0%53 | – | X | |||||
Cognitive impairment (participants scoring 3–7 errors on SPMSQ) | Mini-Cog (3-item recall as needed, if SPMSQ screen+for cognitive impairment) If recall ≥2 words=eligible | 3 | Sensitivity 76%, specificity 89%32 | Sensitivity 99%, specificity 93%54 | X | |||||
Vision | Ability to see words on a newspaper52 | 1 | – | X | ||||||
Health literacy screen for block randomisation (inadequate vs adequate) | ‘How comfortable are you filling out medical forms by yourself?’ ‘Qué tan seguro(a) se siente al llenar formas usted solo(a)’ | 1 | AUROC 0.80 (95% CI 0.67 to 0.93) for inadequate health literacy55 | C-index=0.82, (0.77 to 0.87) for inadequate health literacy56 | X | |||||
Primary outcome | ||||||||||
ACP documentation | ACP Engagement Survey:27 self-report: ACP documentation | 1 | ICC*=0.8727 | – | X | X | X | X | X | |
ACP documentation | Chart review: ACP documentation | X | X | |||||||
Secondary outcomes | ||||||||||
The full ACP Process | ACP Engagement Survey:27 behaviour change process measures (knowledge, contemplation, self-efficacy, readiness) Action measures: values identification and discussions | 108 | Process measures: Cronbach's α=0.94 (0.91 to 0.96), ICC=0.70 (0.54 to 0.82)27 Action measures: ICC*=0.87 (0.79 to 0.92)27 | – | X | X | X | X | X | |
Communication quality | CAHPS (eg, Did this provider explain things in a way that was easy to understand?) | 13 | Comparative Fit Index=0.98, Tucker Lewis Index=0.98 Cronbach's α≥0.70 for constructs39 | Cronbach's α ≥0.70 for constructs and associated with global physician rating40 | X | X | ||||
Satisfaction with communication | (i.e, How satisfied are you that you could share your most important concerns with X/that X understood what was most important to you?) | 8 | – | – | X | X | X | X | X | |
Care consistent with current goals | Care consistent with goals: comparing 10-point scales of patient ratings about aggressiveness of care desired and care currently receiving | 4 | – | – | X | X | X | |||
Satisfaction with decision-making | Decisional Conflict Scale | 20 | Test–retest coefficient=0.81 Cronbach's α: 0.78–0.92 for total scale41 | Cronbach's α=0.8057 | X | X | X | X | ||
Depression | Patient Health Questionnaire-8 | 8 | Scores ≥10 100% sensitive and 95% specific for major depressive disorder42 43 | Scores ≥10 77% sensitive and 100% specific for major depressive disorder58 | X | X | X | X | X | |
Anxiety | GAD-744 | 7 | Cronbach's α=0.9244 ICC*=0.83 | Cronbach's α=0.8845 ICC*=0.64 | X | X | X | X | X | |
Barriers to ACP | Checkbox of common barriers and one open-ended question | 13 | Associated with ACP59 | Associated with ACP59 | X | X | ||||
Attitudes about ACP | Processes of change for ACP31 | 34 | Responsive to an ACP intervention27 | – | X | X | X | X | X | |
Implementation: acceptability | Acceptability and usability (1) Ease of use and understanding (2) Usefulness in decisions and discussions (3) Attitudes about norms or expectations | 8 6 6 | 1 factor explained 81–85% of variance/scale. Kuder-Richardson >0.758 | 1 factor explained 81–85% of variance/scale. Kuder-Richardson >0.758 | X | |||||
Implementation: feasibility | Feasibility (both arms) (eg, when and where to review ACP materials) Feasibility (PREPARE only) (eg, when/where to review and which materials did you use and would recommend to others) | 7 34 | – | – | X | X | ||||
Surrogate reports of patient engagement in ACP | Modified from the ACP Engagement Survey,29 knowledge of patient's wishes, and confidence making decisions, 5-point Likert | 47 | – | – | X | |||||
Moderator variables | ||||||||||
Health literacy assessment | s-TOFHLA scores 0–3660 Continuous and dichotomised to limited=0–22 and adequate=23–36 | 36 | Cronbach's α=0.97 Correlation coefficient with other literacy tests >0.8060 | Cronbach's α >0.9561 | X | |||||
Patient–clinician language concordance | To clinicians: ‘How well do you speak Spanish?62 Fluently, very well (concordant) vs well, fair or poor’ | 1 | AUROC† 94% (CI 90% to 98%)62 | AUROC† 94% (CI 90% to 98%)62 | X | |||||
Desired role in decision-making | CPS with clinicians and family63 | 2 | Correlation between preferred and actual roles in decision-making12 64 65 | Correlation between preferred and actual roles in decision-making66 | X | X | ||||
US acculturation | Based on acculturation scale (USAS) ‘How many years have you lived in the USA?’ | 1 | Cronbach's α=0.98 Associated with desire to know prognosis67 | – | X | |||||
Mediator variables‡ | ||||||||||
Baseline knowledge | Knowledge subscales of the ACP Engagement Survey27 | 6 | Cronbach's α=0.84 (0.76–0.90), ICC*=0.70 (0.50–0.82)27 | – | X | |||||
Baseline self-efficacy | Self-efficacy subscales of the ACP Engagement Survey27 | 6 | Cronbach's α=0.83 (0.75–0.89), ICC*=0.60 (0.41–0.76)27 | – | X | |||||
Baseline readiness | Readiness subscales of the ACP Engagement Survey27 | 10 | Cronbach's α=0.92 (0.88–0.95), ICC*=0.60 (0.53–0.81)27 | – | X | |||||
Baseline ACP barriers | Checkbox of 13 comment barriers59 | 13 | Associated with ACP59 | – | X | |||||
Baseline attitudes about ACP | Processes of change for ACP31 | 34 | Responsive to ACP intervention27 | – | X | |||||
Potential confounders | ||||||||||
Functional status | ADL and IADL measure (13-item)68 69 | 13 | Morbidity/mortality correlation68 69 | Cronbach's α=0.9470 | X | |||||
Self-rated health status | How would you rate your health? (5-point Likert)71 72 | 1 | Cronbach α=0.8072 | – | X | |||||
Self-rated quality of life | How would you rate your quality of life? (5-point Likert)72 73 | 1 | Test–retest coefficient=0.8173 | – | X | |||||
Comorbid illness | Charlson comorbidity score74 75 Elixhauser comorbidity score76 77 | 0 | Mortality c-stat:78 Charlson=0.704 Elixhauser=0.793 | – – | X | |||||
Prior ACP experience | Prior ACP experiences (eg, (Ever had to make life-threatening medical decisions?)8 | 5 | – | X | ||||||
Social support | mMOS-SS79 | 11 | Cronbach's α=0.88–0.9379 | Cronbach's α=0.9480 | X | |||||
Major life changes | For example, ‘In the past 12 months, have you or someone close to you been faced with a serious medical problem or diagnosis?’ | 4 | – | – | X | |||||
Demographic information | ||||||||||
Demographic information | Age, gender, race/ethnicity,81 income, marital status and education | X | X | |||||||
Religion/spirituality | Self-reported extent of how spiritual/religious (five-point Likert) and role play in decision-making82 | 4 | Spirituality associated with quality of life. Religiosity associated with wanting all measures to extend life82 | – | X | |||||
Finances | ‘In general, how do your finances usually work out at the end of the month?’ | 1 | Associated with functional impairment and comorbidity83 | – | X | |||||
Socioeconomic status and social standing | Social standing ladder (ie, place an ‘x’ where you think you stand relative to other people in society) | 1 | Associated with functional decline84 | – | X |
If a validated Spanish version of a survey was not available, we translated the English version into Spanish.
*ICC=intraclass correlation.
†Area under the receiver operating curve (AUROC).
‡While mediator variables, measured at baseline, may explain how or why a particular effect or relationship occurs, these variables may also be affected by the intervention and are therefore also considered secondary outcome variables measured over time (ie, knowledge, self-efficacy and readiness, as well as barriers and attitudes).
ACP, advance care planning; ADL, activities of daily living; CAHPS, Consumer Assessment of Healthcare Providers and Systems; CPS, Control Preference Scale; GAD-7, Generalized Anxiety Disorder 7-Item Scale; IADL, instrumental activities of daily living; mMOS-SS, modified Medical Outcomes Study Social Support; SPMSQ, Short Portable Mental Status Questionnaire; s-TOFHLA, Short form Test of Functional Health Literacy in Adults; USAS, US Acculturation Scale.