The challenge of recruiting patients with anterior cruciate ligament injury of the knee into a randomized clinical trial comparing surgical and non-surgical treatment
(2007) In Contemporary Clinical Trials 28(3). p.295-302- Abstract
- Aims: To determine the number of patients needed to be screened (NNS) and allocated (NNA) in order to include one participant in a randomized clinical trial (RCT), and to compare the characteristics of patients accepting or declining participation in the RCT. Methods: The recruitment process of an ongoing multicenter RCT, comparing surgical and non-surgical interventions after acute anterior cruciate ligament (ACL) injury of the knee is described. We use the known concept Number Needed to Screen (NNS) and introduce the new concept Number Needed to Allocate (NNA) as variables to support a priori sample size calculations of future investigations. Results: 560 patients were screened to identify 162 patients (29%) eligible for inclusion in the... (More)
- Aims: To determine the number of patients needed to be screened (NNS) and allocated (NNA) in order to include one participant in a randomized clinical trial (RCT), and to compare the characteristics of patients accepting or declining participation in the RCT. Methods: The recruitment process of an ongoing multicenter RCT, comparing surgical and non-surgical interventions after acute anterior cruciate ligament (ACL) injury of the knee is described. We use the known concept Number Needed to Screen (NNS) and introduce the new concept Number Needed to Allocate (NNA) as variables to support a priori sample size calculations of future investigations. Results: 560 patients were screened to identify 162 patients (29%) eligible for inclusion in the RCT. 41 of those declined participation for various reasons, the most common being unwillingness to undergo surgery (n=23) or unwillingness to risk conservative treatment (n=8). 19 patients were excluded after MRI assessment or arthroscopy. Thus, 102 (18%) patients were allocated to one of the two treatments in the RCT. The NNS was 5.5 individuals with an acute knee injury, and the NNA was 1.6 individuals eligible for inclusion, to include I patient in the RCT. Patients declining to participate in the RCT were more frequently self-employed and less frequently injured in sports activities than those accepting RCT participation. Conclusions: We suggest that the a priori sample size calculation needs to be multiplied by at least 5.5 to provide an estimate of the number needed to screen, or 1.6 to provide an estimate of the number needed to allocate in order to include the desired number of patients in a trial comparing surgical and non-surgical treatment of the ACL injured patient. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/668556
- author
- Frobell, Richard LU ; Lohmander, Stefan LU and Roos, Ewa LU
- organization
- publishing date
- 2007
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- rehabilitation, knee, sample size, randomized controlled trials, patient selection, surgical ligament, reconstruction, anterior cruciate ligament injuries, injuries
- in
- Contemporary Clinical Trials
- volume
- 28
- issue
- 3
- pages
- 295 - 302
- publisher
- Elsevier
- external identifiers
-
- wos:000245339800009
- scopus:33847322498
- pmid:17137844
- ISSN
- 1551-7144
- DOI
- 10.1016/j.cct.2006.10.002
- language
- English
- LU publication?
- yes
- id
- 278a15e8-0cfc-47ef-9158-1e05030cfc3b (old id 668556)
- date added to LUP
- 2016-04-01 12:19:35
- date last changed
- 2023-01-03 06:59:03
@article{278a15e8-0cfc-47ef-9158-1e05030cfc3b, abstract = {{Aims: To determine the number of patients needed to be screened (NNS) and allocated (NNA) in order to include one participant in a randomized clinical trial (RCT), and to compare the characteristics of patients accepting or declining participation in the RCT. Methods: The recruitment process of an ongoing multicenter RCT, comparing surgical and non-surgical interventions after acute anterior cruciate ligament (ACL) injury of the knee is described. We use the known concept Number Needed to Screen (NNS) and introduce the new concept Number Needed to Allocate (NNA) as variables to support a priori sample size calculations of future investigations. Results: 560 patients were screened to identify 162 patients (29%) eligible for inclusion in the RCT. 41 of those declined participation for various reasons, the most common being unwillingness to undergo surgery (n=23) or unwillingness to risk conservative treatment (n=8). 19 patients were excluded after MRI assessment or arthroscopy. Thus, 102 (18%) patients were allocated to one of the two treatments in the RCT. The NNS was 5.5 individuals with an acute knee injury, and the NNA was 1.6 individuals eligible for inclusion, to include I patient in the RCT. Patients declining to participate in the RCT were more frequently self-employed and less frequently injured in sports activities than those accepting RCT participation. Conclusions: We suggest that the a priori sample size calculation needs to be multiplied by at least 5.5 to provide an estimate of the number needed to screen, or 1.6 to provide an estimate of the number needed to allocate in order to include the desired number of patients in a trial comparing surgical and non-surgical treatment of the ACL injured patient.}}, author = {{Frobell, Richard and Lohmander, Stefan and Roos, Ewa}}, issn = {{1551-7144}}, keywords = {{rehabilitation; knee; sample size; randomized controlled trials; patient selection; surgical ligament; reconstruction; anterior cruciate ligament injuries; injuries}}, language = {{eng}}, number = {{3}}, pages = {{295--302}}, publisher = {{Elsevier}}, series = {{Contemporary Clinical Trials}}, title = {{The challenge of recruiting patients with anterior cruciate ligament injury of the knee into a randomized clinical trial comparing surgical and non-surgical treatment}}, url = {{https://lup.lub.lu.se/search/files/2877512/1057228.pdf}}, doi = {{10.1016/j.cct.2006.10.002}}, volume = {{28}}, year = {{2007}}, }