Caroline B Terwee1, Martine H P Crins2, Leo D Roorda2, Karon F Cook3, David Cella3, Niels Smits4, Benjamin D Schalet3. 1. Amsterdam UMC, Vrije Universiteit Amsterdam, Epidemiology and Data Science, Amsterdam Public Health Research Institute, de Boelelaan 1117, Amsterdam, the Netherlands. Electronic address: cb.terwee@amsterdamumc.nl. 2. Amsterdam Rehabilitation Research Center Reade, Amsterdam, the Netherlands. 3. Department of Medical Social Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. 4. Research Institute of Child Development and Education, University of Amsterdam, Amsterdam, the Netherlands.
Abstract
OBJECTIVE: PROMIS offers computerized adaptive tests (CAT) of patient-reported outcomes, using a single set of US-based IRT item parameters across populations and language-versions. The use of country-specific item parameters has local appeal, but also disadvantages. We illustrate the effects of choosing US or country-specific item parameters on PROMIS CAT T-scores. STUDY DESIGN AND SETTING: Simulations were performed on response data from Dutch chronic pain patients (n = 1110) who completed the PROMIS Pain Behavior item bank. We compared CAT T-scores obtained with (1) US parameters; (2) Dutch item parameters; (3) US item parameters for DIF-free items and Dutch item parameters (rescaled to the US metric) for DIF items; (4) Dutch item parameters for all items (rescaled to the US metric). RESULTS: Without anchoring to a common metric, CAT T-scores cannot be compared. When scores were rescaled to the US metric, mean differences in CAT T-scores based on US vs. Dutch item parameters were negligible. However, 0.9%-4.3% of the T-score differences were larger than 5 points (0.5 SD). CONCLUSION: The choice of item parameters can be consequential for individual patient scores. We recommend more studies of translated CATs to examine if strategies that allow for country-specific item parameters should be further investigated.
OBJECTIVE: PROMIS offers computerized adaptive tests (CAT) of patient-reported outcomes, using a single set of US-based IRT item parameters across populations and language-versions. The use of country-specific item parameters has local appeal, but also disadvantages. We illustrate the effects of choosing US or country-specific item parameters on PROMIS CAT T-scores. STUDY DESIGN AND SETTING: Simulations were performed on response data from Dutch chronic painpatients (n = 1110) who completed the PROMIS Pain Behavior item bank. We compared CAT T-scores obtained with (1) US parameters; (2) Dutch item parameters; (3) US item parameters for DIF-free items and Dutch item parameters (rescaled to the US metric) for DIF items; (4) Dutch item parameters for all items (rescaled to the US metric). RESULTS: Without anchoring to a common metric, CAT T-scores cannot be compared. When scores were rescaled to the US metric, mean differences in CAT T-scores based on US vs. Dutch item parameters were negligible. However, 0.9%-4.3% of the T-score differences were larger than 5 points (0.5 SD). CONCLUSION: The choice of item parameters can be consequential for individual patient scores. We recommend more studies of translated CATs to examine if strategies that allow for country-specific item parameters should be further investigated.
Authors: Isolde A R Kuijlaars; Lorynn Teela; Lize F D van Vulpen; Merel A Timmer; Michiel Coppens; Samantha C Gouw; Marjolein Peters; Marieke J H A Kruip; Marjon H Cnossen; Jelmer J Muis; Evelien S van Hoorn; Lotte Haverman; Kathelijn Fischer Journal: Res Pract Thromb Haemost Date: 2021-11-21
Authors: Anne Kaman; Christiane Otto; Janine Devine; Michael Erhart; Manfred Döpfner; Tobias Banaschewski; Anja Görtz-Dorten; Charlotte Hanisch; Michael Kölch; Veit Roessner; Ulrike Ravens-Sieberer Journal: Qual Life Res Date: 2021-09-29 Impact factor: 4.147