This study aimed to determine whether responses to Patient-Reported Outcomes Measurement Information System Short Form v2.0 – Physical Function 8c (PROMIS PF8c) items differed when the use of a 7-day recall period was compared with no specified recall period.
Using a within-subject design, we surveyed 1810 individuals from the US general population, administering PROMIS PF8c at survey beginning and end. The order of measure presentation was randomly assigned. We calculated recall difference scores (RDSs) as no recall score minus 7-day recall score using both item response theory-based T scores and raw summed scores. We examined the distribution and created Bland-Altman plots for both RDS and RDS . We also calculated correlations between no recall versus 7-day recall T score and raw scores. Finally, we determined whether differences in no recall versus 7-day recall scores were associated with patient-reported PF.
RDS and RDS had means (root mean square differences) of 0.00 (5.43) and −0.04 (3.79), respectively. The vast majority (%) of RDS and RDS values fell between the Bland-Altman limits of agreement (−10.65 to 10.66 and −7.46 to 7.38, respectively). Pearson’s correlations between no recall and 7-day recall for T scores and raw scores were 0.88 and 0.87, respectively. Effect sizes for mean RDS and RDS compared across level of Eastern Oncology Cooperative Group performance status, patient global impression of PF severity, and single PF items were near 0.
We did not find any significant recall period effect on PF8c responses. Therefore, we recommend the use of the PROMIS physical function standard, with no specified recall time period.