123.
Reliability of patient reported outcome in a joint replacement
registry: no response bias found in the Danish Shoulder Arthroplasty
Registry
Anne Polk, Jeppe Vejlgaard Rasmussen, Stig Brorson, Bo Sanderhoff Olsen
Orthopaedic Surgery Herlev hospital; Orthopaedic Surgery, Herlev hospital;
Orthopaedic Surgery, Herlev hospital; Orthopaedic Surgery, Herlev hospital
Background:
Patient-reported outcome measures (PROMs) are used by some
arthroplasty registries to evaluate results after surgery, but non-response may
bias the results.
Purpose / Aim of Study:
The aim was to identify a potential bias in a cohort
of patients from the Danish Shoulder Arthroplasty Registry (DSR) and to
characterize non-responders.
Materials and Methods:
Patient reported outcome of 787 patients operated in
2008
was assessed 12 months postoperatively using the Western Ontario
Osteoarthritis of the Shoulder index (WOOS). In January 2012 non-
responders and incomplete responders were sent a postal reminder. Non-
responders of the postal reminder were contacted by telephone. Total WOOS-
score and WOOS-subscales were compared for initial responders, responders
of the postal reminder and responders after telephone contact. Predefined
variables age, gender, diagnosis, geographical region and reoperation rate were
compared for responding and non-responding cohorts.
Findings / Results:
A postal reminder increased the response rate from 64,7 %
(5,7%
incomplete) to 80,3 % (3,0 % incomplete) and telephone contact
resulted in further increase to 82,4 % (2,1 % incomplete). No clinically or
statistically significant differences in total WOOS-score or any WOOS-
subscales were found between responders of the first questionnaire, responders
of the postal reminder and responders after telephone contact. The response
rate was statistically significantly lower for younger patients.
Conclusions:
Non-responders did not seem to bias the overall results after
shoulder replacement. As response rates rose markedly by implementation of
postal reminders, we recommend the implementation of reminders in
arthroplasty registries using PROMs.
