Cross-Cultural Validation of PROs is more than language translation

A fairly late night and long day today, so missed our chance for a good video update as the sunlight burned off quickly.  We've spent the day in Twillingate Newfoundland, a historic city of just over 2,000 permanent residents originally settled by the french.  It's gone through several hundred years of ups and downs and according to the local residents, is currently experiencing a bit of a down in terms of economy and jobs especially for younger people.  In wandering around this town not only have I been awestruck by my first experience seeing icebergs (they are STUNNING!), but it also got me thinking about the way we use patient-reported outcomes (PROs) to measure mobility issues in our patients.  Some of you will be familiar with common physio PROs like the Lower Extremity Functional Scale (LEFS) or the Upper Extremity Functional Index (UEFI).  My mind immediately went to some of the questions on the LEFS, in particular ones asking about difficulty walking a block, walking a mile, or running on even or uneven ground.  While having a wander round Twillingate I tried to imagine how residents of this quaint fishing town with its homes shoved literally into the side of some of the hills around the area would answer those questions.  There are no 'blocks' here, so a question about difficulty walking a block would have no meaning.  I doubt many of the residents I've seen run all that often, yet in some cases the 'simple' act of walking from their home to their outbuildings is likely biomechanically and energetically speaking just as difficult as running (at least running on even ground), so they may indicate they don't run on even ground, yet mobility-wise are likely very capable - perhaps moreso than those of us who run on even ground.  And then there was the story of a patient who described the mechanism of her lower extremity injury to her doctor as 'I jumped off my bridge' to which her doctor (not a local) responded with concern about her clear suicidality.  As it turns out, your 'bridge' in newfoundland-ish is the front step of your house.

Here's my point of this - many scales we use (or arguably should be using) have been tested for adequate properties of validity and reliability.  The good ones will then usually get picked up by people from other global regions but before then can be implemented they must be 'cross-culturally adapted'.  In every single case I can think of, cross-cultural adaptation has been in fact the process of a language translation, with the presupposition that people who speak the same language, or at least who live in the same country, must necessarily interpret the items in the scale the same way.  Yet this is the value of the firsthand experience I've already gained on this project - clearly this presupposition is incorrect.  Perhaps it's time we start looking at our tools, in particular in a country as geographically and culturally-diverse as Canada, as requiring cross-cultural 'validation' (or even translation) in the same language and within the same country.  I seriously can't think of a single time this has happened so correct me if you know of one, but I can tell you the good, hard-working folks here in Twillingate would have a rough time fully completing the LEFS, and I'm fairly certain the way they do respond would give their clinicians an inaccurate view of their actual mobility.