Improving Quality Based on the Joint Registry
Phase: NA
Conditions: Registries, Quality Improvement, Hip Arthropathy, Knee Arthropathy, Hospital Performance
Sponsor: Leiden University Medical Center

 
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RESEARCH PROTOCOL 
Application non-WMO statement 
GENERAL INFORMATION 
 
 
RESEARCH INFORMATION 
 
Rationale 
Improving quality in knee and hip replacement surgery by frequent 
feedback of data from the Landelijke Registratie Orthopedische 
Implantaten (LROI), supplemented with additional data from participating 
center. In the favorable case patient care will improve. 
 
Study objectives 
1) Retrospective observational study (LROI database) 
Gain more insight into variation in Dutch hospital performance on 
different outcomes after primary hip- and knee replacement. 
Variation will also be determined when outcomes are combined 
into hospital performance profiles. In addition, it will be 
determined to what extent the variation is explained by patient-
mix, type of prosthesis, pre-and postoperative processes or other 
factors. In addition, we want to test to what extent outliers in the 
annual funnel plot, can be signaled in an earlier phase using 
Statistical Process Control (SPC) analyses. 
 
2) Randomized Controlled Trial (RCT) 
Test whether an intervention, consisting of frequently feedback of 
performance data (LROI data and additive data from participating 
center) and education will improve patient care, expressed in 
better functional outcomes, fewer complications and more quality 
Title 
What makes a best performing hospital in hip and knee replacement? 
Quality improvement using joint registry data. 
 
Date 
24 October 2018 
 
Version number 
Version 1 
 
Coordinating investigator 
Drs. P. van Schie 
 
Principal investigator(s) 
Prof. dr. R.G.H.H. Nelissen 
Dr. P.J. Marang-van de Mheen 
 
Sponsor 
Van Rens Fonds 
 
Subsidy application 
Annex 1; Subsidy Application; IQ Joint Study 
 
Data delivery agreement 
Annex 2; Data Delivery Agreement; IQ Joint Study 
 

 
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improving interventions.  
 
Study design 
1) Retrospective observational study 
The variation in performance between Dutch hospital will be 
determined after hip and knee replacement by a retrospective 
observational study using the available data from the Dutch 
orthopedic implant registry (LROI). 
 
2) Randomized Controlled Trial 
All hospitals performing hip- and/or knee replacement will be 
invited to participate in the study to test the effectiveness of a 
multifaceted intervention strategy (see interventions). 
Participating hospitals will be randomized to an early versus late 
group. In the first period, the early group will receive the 
intervention and will be compared with the other group receiving 
usual care. In the second period, the early group should be able to 
sustain the interventions in daily practice (so not actively 
supported anymore) and will be compared with the late group 
now receiving the intervention.  
 
Study population 
1) Retrospective observational study 
All patients who underwent a hip- and/or knee replacement in the 
period 2014-2016 are extracted from the LROI database. 
 
All data are anonymized, both on patient and hospital level 
 
In this period relevant case-mix factors are available (e.g. ASA 
class, Charnley comorbidity score, BMI and smoking) 
 
2) Randomized controlled trial  
        Eighteen orthopedic clinics that perform hip-/knee replacements. 
 
Inclusion criteria 
1) Retrospective observational study 
All patients who underwent hip- and/or knee replacement 
between 2014-2016 will be extracted from the LROI database. 
 
2) Randomized clinical trial  
All orthopedic clinics where hip- and knee replacement surgery is 
performed who agree to participate will be randomized.  
 
Exclusion criteria 
None 
 
Sample size 
1) Retrospective observational study 
Hip: 80.000 patients (2014-2016) 
Knee: 75.000 patients (2014-2016) 
 
2) Randomized clinical trial 
Power calculation has shown that at least 18 participating 
hospitals (9 in each arm) are needed to be able to detect a 
difference in performance on the composite outcome of 70% 
versus 80% with 80% power and 95% reliability (assuming an 

 
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intra-hospital correlation of 0.02 and a median of 100 procedures 
per hospital, separately for hip and knee replacement).  
 
Recruitment method 
 
The Nederlandse Orthopaedische Vereniging (NOV) and the 
LROI posted a message on their website 
 
The NOV has sent an email to all orthopedic surgeons to bring 
the study under attention 
 
At this moment 18/18 hospitals will participate in the study 
 
Intervention 
Randomized controlled trial 
 
Monthly feedback of performance outcomes 
 
Active education on how to use performance outcomes from  
joint registry data for quality improvement 
 
Create awareness by asking about (type of) improvement 
activities + their performance in regular surveys. Awareness 
will also be increased by the education. 
 
Hospitals will be linked to hospital with opposite performance 
outcomes to exchange information and find areas for 
improvement. 
 
Main study parameters 
1) Retrospective observational study (LROI database) 
 
Variation in following outcomes: 
o 
Revision rate (<1 year) 
o 
Mortality 
o 
Patient Reported Outcome Measures (PROMs) 
 
2) Randomized controlled trial 
 
The effect of the intervention on: 
o 
Number of quality improvement interventions 
undertaken 
o 
Awareness of their own performance 
o 
Number of people attending quality meetings 
o 
Revision rate; PROMs; Length of stay; Readmissions; 
Reoperations; Complications (wound infections) 
o 
Composite outcome (in which aforementioned 
variables are integrated) 
 
Statistical analyses 
       1)    Retrospective observational study 
 
Variation in hospital performance outcomes, observed versus 
expected based on patient mix using logistic regression 
models to calculate expected probability based on total 
population. The variation is shown in funnel plots. 
 
The extent to which an outlier in the annual funnel plot can 
be signaled earlier by using SPC techniques. 
 
2)   Randomized controlled trial 
 
Variation in performance outcomes of participating hospital 
will be compared to performance outcomes in non-
participating hospitals before the start of the RCT by using 

 
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LROI data. 
 
Comparing the intervention with the control group after 
period 1 and after period 2 (see main study parameters) using 
the appropriate regression analysis depending on the 
outcome parameter. When looking at patient outcomes, the 
clustering of patients within hospitals will be taken into 
account. 
 
Generate a composite outcome and determine the 
correlation to individual components of the composite 
outcome. 
 
Reliability of ranking hospitals by using the composite 
outcome. 
 
Nature and extent of the 
burden and risks associated 
with participation 
 
The participating hospital has to links LROI data to available 
data from other sources and anonymize them before sending 
to coordinating investigator. We create a manual and 
example file to facilitate.  
 
Participation in educational meetings and interviews among 
orthopaedic surgeons. 
 
The participating centre must report in logbook which quality 
improving interventions are undertaken and monitor whether 
these are effective.  
 
Benefits of participating 
For participating hospitals, this study is an opportunity to improve their 
quality of care through a frequent and clear feedback of the collected 
information in the LROI with additional collected data. The data can give 
leads to improving patient care and they are able to test a new way of data 
feedback, with possibilities of earlier detection of deviating performance.  
 
Disadvantages of 
participating 
Some may be hesitant to disclose of the performance data to a buddy 
hospital and their peers. In addition it takes time for the data link setup 
and participation in the interviews and educational meetings as well as 
monitoring performance on improvement activities.  
 
Administrative aspects 
Data obtained from the LROI database and data from the participating 
hospitals will be anonymized and placed on a secure drive. 
 
Publication policy and 
amendments 
Articles will be submitted after approval of all authors.