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The questionnaire most frequently used worldwide to measure physical disability in rheumatic diseases is the Stanford Health Assessment Questionnaire (HAQ) Disability Index.1 In 2001, the Nijmegen group published a quite literal Dutch translation of the questionnaire2 to replace their version of 1990.3 Two other translations exist: from Leiden (1984)4 and Utrecht (Vragenlijst Dagelijks Functioneren, 1990).5 All translations have been validated to some extent and have seen extensive use, coexisting in parallel without any major problems.
Unfortunately, the 2001 Dutch HAQ did not replace the other versions. This is not unique to The Netherlands and may be inconsequential,6 but using one common version would be better. MB invited representatives from Utrecht, Nijmegen and Leiden to formulate a consensus instrument that would retain the most desirable properties of each version, without requiring further validation.
We started with the Nijmegen 2001 version as it is the most recent and most closely in agreement with the original instrument. MB listed the contents and differences between the three versions and suggested compromise solutions. The other team members modified these in several e-mail rounds. A few remaining issues were resolved in a face-to-face meeting.
Major differences include deleted and extra items, the handling and number of aids and one item that fails to capture the original item in all versions (table 1). Minor differences include choice of words, headings (dimensions) and instructions.
We decided to delete the extra items in the Leiden and Utrecht versions and follow the original questionnaire in the handling of aids. The problematic item is in the dimension “Reach”, original wording:
Are you able to: – Reach and get down a 5-pound object (such as a bag of sugar) from just above your head?
The problem is the metric system followed in mainland Europe: 5 pounds US translates to 2.25 kg, not a standard packaging weight for sugar in Europe. Thus, Leiden and Nijmegen reduced the weight to 1 kg, making the task easier, and Utrecht chose a 2.5 kg object such as a heavy (cooking) pan, an object dissimilar to the sugar bag (eg, hard, has handles). In the consensus HAQ, we chose an object resembling a bag of sugar, but locally available in a 2.5-kg package: potatoes or rice. Thus, the item becomes:
Are you able to: – Reach and get down an object of about 2.5 kg (such as a bag of potatoes or rice) from just above your head?
Issues beyond translation remain and need to be resolved at the international level. These include the scoring method for the use of aids or devices (aids and devices not formally linked to a specific dimension of the HAQ) and the handling of missing data.
To implement the consensus version in research and clinical practice in The Netherlands, it will be published in the Netherlands Journal for Rheumatology. Moreover, all rheumatologists will receive an announcement of its publication (freely downloadable) on the website of the Dutch Society for Rheumatology: http://www.nvr.nl/meetinstrumenten
We thank Jaap Fransen, Hans Bijlsma and Suzan Verstappen for their help.
Competing interests: None.
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