Table 1.

Predetermined decision rules for item inclusion, exclusion, and revision for phases I–III

Phases	Predetermined decision rules
Phase I
Literature review
Include	Activities that could be considered IADL
Step 1. Activities ‘pilot study’
Include	32 pilot study IADL activities
Exclude	≥ 2 HCPs: Not considered IADL < 3 Pt/Pr/HCPs: Affected
Revision	≥ 2 Pt/Pr/HCPs: Unclear; rephrase or, if this was not possible, exclude
Steps 2 & 3. Semi-structured interviews
Include	≥ 2 Pt/Pr/HCPs:  New activity generated that could be considered IADL
Exclude	≥ 6 HCPs: Mean relevance & importance < 2.0 (unless ≥ 2 HCPs in top 10) or Not relevant
Step 4. Cognitive debriefing
Exclude	≥ 2 Pt/Pr/HCPs: Activities are too similar (redundancy)
Revision	≥ 2 Pt/Pr/HCPs: Unclear; rephrase or, if this was not possible, exclude
Phase II
Activities converted to items
Revision	Revisions based on recommendations from the Translation Unit to be applicable in all languages
Phase III
Newly generated items
Include	≥2 Pt/Pr: New activity generated that could be considered IADL
Round 1: Per geographical region
Exclude	Pt: Not in the top 10 most important items and  < 60% score 3 or 4 on both importance & relevance and Mean score < 2.0 on difficulty with item (N/A responses excluded)
Round 2: All geographical regions
Exclude: (in > 1 region & unless in top 10 most important)	Pt: < 60% score 3 or 4 on both importance & relevance or ≥ 75% ‘Not applicable’
Round 3: All geographical regions
Exclude: (in > 1 region & unless in top 10 most important)	Pt: Prevalence ratio > 30% or Floor or ceiling effect scores 1&2 or 3&4 were > 20% or Compliance rate ≤ 95% or Range ≤ 2 points
Acceptability
Revision per region	> 5 Pt&Pr: Rate item difficult/confusing/annoying/upsetting
Revision all regions	> 5% Pt&Pr (8.5 Pt&Pr): Rate item difficult/confusing/annoying/upsetting

Pt patients, Pr proxies, HCPs health care professionals, IADL instrument activities of daily living