Effectiveness of Total Hip Arthroplasty for Patients With Osteoarthritis, a Target Trial Emulation Study
Conditions: Hip Osteoarthritis
Sponsor: JointResearch

 
 
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Template research protocol (non-WMO) 
 
STUDY DATA 
Research title 
Effectiveness of total hip arthroplasty for patients with osteoarthritis, a 
target trial emulation study using Santeon data. 
Acronym/ short study title 
EAGLE 
Date / Version 
17-5-2023 
Study number 
SDB 2023-002 
Type of study 
☒ 
Retrospective study (file/status review) 
Prospective study with questionnaires, interviews, etc.  
 
 
Principal investigator 
this must be a staff member of a 
Santeon Hospital 
Prof R.W. Poolman, orthopedic surgeon 
Executive researcher(s) 
A.D. Klaassen, PhD candidate and orthopedic researcher, OLVG 
W. Jorritsma, data analyst value-based health care (VBHC), OLVG 
N.W. Willigenburg, research coordinator, OLVG 
A.J. de Vries, research coordinator, Martini hospital 
Researchers Participating 
Santeon Hospitals 
Data  
Note the name, position, and hospital of the local 
principal investigator per Santeon Hospital (this must 
be a staff member) 
(It is not mandatory for all Santeon Hospitals to 
participate) 
Signature 
1 
Rudolf W. Poolman, Orthopedic 
surgeon  
OLVG 
 

 
 
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Petitioner 
(The person who submits the 
study to the Management 
Committee) 
Name: Amanda Klaassen 
Function, department and hospital: 
Researcher and quality officer orthopedic department, OLVG 
Phone number: 020 599 2572 / 06-53437040 
Email address: a.d.klaassen@olvg.nl 
The study is conducted 
under: 
☒ 
General scientific research 
☐ 
PhD research  
 
 
☐ 
Other, namely: <click here if you want to enter text> 
 
 

 
 
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SUMMARY 
The ideal research design to investigate effectiveness of total hip arthroplasty (THA) compared to no 
surgery, would be to randomize patients between surgery and non-surgery. However, such a randomized 
controlled trial (RCT) is deemed unethical due to the effect size of THA shown in observational studies. 
To our knowledge, the effect of THA has never been investigated through an RCT, however, the effect 
and importance of THA for patients and society seems to be underestimated in observational studies.  
 
During the Covid-19 pandemic elective orthopedic interventions such as THA were often cancelled and 
the waiting time to surgery increased. Independent of patient characteristics and potential prognostic 
factors, some surgeries could be performed and other surgeries were cancelled and patients remained 
on the waiting list, this circumstance allows for a natural experiment. We aimed to perform a target trial 
emulation (TTE) study on the effect of THA (1). In this study we will compare changes in hip disability in 
patients with hip osteoarthritis between two groups: THA versus non-surgery (due to the delay in surgery 
due to the covid pandemic).  
 
We hypothesize that THA is effective compared to non-surgery in reducing hip disability in patients with 
hip osteoarthritis measured with the Hip disability and Osteoarthritis Outcome Score Physical function 
Short form (HOOS-PS). 
 
The secondary aim of our study is to assess effectiveness of THA with respect to pain measured with a 
numerical rating scale (NRS) during weight bearing.  
 
1. INTRODUCTION 
 
Total hip arthroplasty (THA) is one of the most frequently performed orthopedic surgeries. Studies show 
that THA is an effective treatment to reduce pain and to improve hip function and quality of life in 
patients with osteoarthritis of the hip. However, the effectiveness of THA has never been investigated by 
means of a randomized controlled trial (RCT), which is the gold standard to assess effectiveness of an 
intervention. 
During the Covid-19 pandemic, elective orthopedic interventions were defined as not urgent and 
therefore cancelled. The National Institute for Public Health and the Environment (RIVM) estimated that 
in 2020 and 2021 in total 32,000 Quality-Adjusted Life Years (QALYs) were not realized due to postponing 
THA in patients with osteoarthritis of the hip in the Netherlands (9, 10). Better understanding of the 
treatment effect of THA, compared to non-surgery, could help improve prioritization of interventions.  
The ideal research design to investigate effectiveness of THA would be to randomize patients between 
surgery and (delayed) non-surgery. Such an RCT is deemed unethical due to the effect size of THA shown 
in observational studies. It is considered unethical to withhold the patients who are allocated to the 
conservative treatment from the apparent benefits of THA. The required investments in time and money 
to perform an RCT and expected difficulty to include sufficient patients do not outweigh the benefits of 
measuring the effect of THA to demonstrate its urgency. Moreover, a potential benefit of research with 
observational data is, that it better reflects real-world data.  
During Covid-19, there were different phases of hospital reduction and restoring of surgical capacity. 
During periods when surgeries were scaled down nationwide, only emergency surgeries for fractures, 
infections, and revisions were performed in the orthopedic department. However, our study specifically 

 
 
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focuses on elective primary total hip replacements for osteoarthritis, and during the research period, 
there was no prioritization based on the severity of symptoms within this osteoarthritis population. 
Within the COVID period there were various periods of scaling up and down surgical capacity for elective 
hip operations, caused by external factors. For example, patient A, scheduled for surgery on Tuesday, 
proceeded, while patient B, scheduled for Thursday, had to be rescheduled due to changed government 
or regional policy effective the next day. Patient C had surgery while patient D was cancelled because the 
surgeon suddenly had to quarantine due to a child or partner with a COVID infection. These issues 
caused that in some patients THA could be performed and in other patients THA was cancelled.  
We assume that whether or not such surgeries took place during the COVID period was beyond the 
control of patients, doctors and researchers and can be seen as a form of (pseudo)randomization. In a 
traditional RCT, randomization is done by means of computerized random sequence generation. In an 
emulation trial (1, 11), randomization is introduced by factors outside of our control, in this case whether 
THA surgery was cancelled or not due to the COVID-19 pandemic and the resulting scarcity of operating 
rooms for THA surgery. 
An important step in RCT emulation is to verify the validity of the assumption that a comparison between 
two groups (in our study patients who did and who did not undergo THA surgery within the COVID 
period) is indeed (pseudo)random and requires analysis. The answer to this question is an outcome of 
the research, not something we can determine with certainty in advance.  
Therefore, the aim of this study is to measure if THA is effective in restoring physical function in patients 
with osteoarthritis of the hip compared to non-surgery in existing Value-Based Health Care (VBHC) data 
by means of RCT Target Trial Emulation.  
2. RESEARCH QUESTION/ RESEARCH OBJECTIVE 
 
The primary aim of this study is to measure if THA is effective to reduce disability in physical function in 
patients with osteoarthritis of the hip compared to non-surgery by means of RCT Target Trial Emulation. 
We hypothesize that THA is effective compared to non-surgery in reducing hip disability in patients with 
hip osteoarthritis measured with the Hip disability and Osteoarthritis Outcome Score Physical function 
Short form (HOOS-PS). 
Secondary aims of this study are to assess improvement in terms of pain during weight bearing measured 
on a numerical rating scale (NRS) and assess patient reported improvement in functioning and pain 
measured by an anchor based question. We hypothesize that THA is effective compared to non-surgery 
in reducing pain.  
 
3. METHODS 
 
3.1 Study design 
 
Hip osteoarthritis patients eligible for THA and placed on the waiting list for surgery will be included when 
the preoperative intake questionnaire is completed between 1-4-2020 and 1-1-2022. In a retrospective 
dataset we compare two standard care strategies: THA and wait-and-see, in which patients did not 
receive THA and remain on the waiting list. Patients were assigned to one of the two groups based on 

 
 
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whether surgery could be performed or whether THA was cancelled and patients remained on the waiting 
list. The first group (THA group) consists of patients that received surgery before 1-1-2022 and completed 
a 3-months postoperative questionnaire before 1-4-2022. The second group (control group) consists of 
patients which did not receive surgery before 1-1-2022 and completed a waiting list questionnaire before 
1-4-2022. The target trial and emulation plan are shown in Figure 1 and the time-schedule of the 
emulation trial is shown in Figure 2. Patients that received THA on both sides between 1-4-2020 and 1-1-
2022 will be excluded. The response rates on follow-up questionnaires will be reported for both groups. 
We will compare characteristics (age, sex, PROM-outcomes at baseline and physical therapy before the 
hospital visit) for patients that completed the follow-up questionnaires (completers) and patients that did 
not complete the follow-up questionnaires (non-completers). In the primary analysis we will correct for 
patient characteristics. 
 
 
 Figure 2: Timeline target trial emulation  
THA= Total Hip Arthroplasty  
FU = Follow-up 
apr-20
jul-20
okt-20
jan-21
mei-21
aug-21
nov-21
mrt-22
Baseline (intake)
Orthopaedic visit (randomization)
Intervention: No THA
Intervention: THA
FU: Waiting list questionnaire
FU: Post-OK questionnaire
Timeschedule target trial THA vs no THA
Start date
Days in total

 
 
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In this study we compare the effect of THA compared to non-surgery on hip disability measured with the 
HOOS-PS change score from baseline up to approximately 3-months by means of RCT Target Trial 
Emulation, which aims to mimic a traditional RCT. Function and pain as a secondary outcome are 
measured by means of patient reported outcome measures (PROMs) pre-operatively and post-operatively 
or post-waiting list. The pre-operative intake questionnaire and the 3-months postoperative 
questionnaire are part of standard care. The waiting list questionnaire was administered during the Covid-
19 pandemic to monitor patients' health status in two Santeon Hospitals (OLVG and Martini) in all 
patients who were at least three months on the waiting list. Therefore our study will be performed with 
data of these two Santeon Hospitals. All data is available through the routinely collected data for hip 
osteoarthritis within the VBHC program and in addition the outcomes of the administered waiting list 
questionnaire. Therefore, it is not needed to obtain additional information from patients.  
 
To test the assumption that group allocation is (pseudo)random and cannot be explained by patient 
characteristics or severity of pain and hip disability at baseline, a logistic regression analysis will be 
performed on patients within the VBHC data set between 1-4-2020 and 1-1-2022. Group being the 
dependent variable (THA vs. non-surgery) and age (continuous), sex (M/F), physical therapy before the 
hospital visit (yes/no), follow-up time in days (continuous), pain at baseline (NRS, continuous) and the 
HOOS-PS at baseline (continuous) will be included in the model as independent variables. Secondly, we 
will test the assumption that follow-up time in days is not statistically significantly different between the 
THA and non-surgery group.  Follow-up time is defined by calculating the number of days between the 
date of the orthopedic visit) and the date of the follow-up questionnaire. Results will be considered 
statistically significant when p≤0.05. In case an independent variable has a statistically significant effect on 
group assignment and/or follow-up time in days is significantly different between the two groups, clinical 
relevance will be considered and discussed within the research team, for example the effect size on 
chance to be allocated to the THA or non-surgery group. 
 
We hypothesize that patient characteristics (i.e. sex, age, severity of symptoms at baseline) do not affect 
group allocation and follow-up time is similar for THA and non-surgery patients. If this is true, the 
proposed Target Trial Emulation will provide the first evidence on the effectiveness of THA surgery in 
terms of causal inference. 
 
3.2 Procedure and intervention (if applicable) 
This is a retrospective study and all procedures have already been performed within standard care. In a 
retrospective dataset we compare two standard care strategies: THA and wait-and-see, in which patients 
did not receive THA and remain on the waiting list.  
1.1 Duration of study 
The study will be conducted with existing data starting from 1-4-2020 up until 31-3-2022. Patients on the 
waiting list for THA and with a completed intake questionnaire between 1-4-2020 and 1-1-2022 are 
included for this study and outcomes will be collected up until 31-3-2022. Mean follow-up time in days 
will be calculated for both the THA and non-surgery group. The timeline for this target trial emulation is 
presented in figure 2.  
1.2 Recruitment and selection of subjects 
1.2.1 
Screening/selection 
Retrospective data will be collected by A.D. Klaassen and the VBHC data analysts at OLVG and Martini 
hospital.  

 
 
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1.2.2 
Study population 
 
Patients with hip osteoarthritis that were on the waiting list for THA between 1-4-2020 and 1-1-2022 and 
had a completed intake questionnaire will be included. The number of patients is dependent on how 
many patients completed the questionnaires and needs to be investigated. However, based on the 
waiting list at the time and the number of performed surgeries in the two hospitals, we expect to include 
at least 100 patients in each cohort (THA group and non-surgery group). Since we use observational data 
for trial emulation, no sample size calculation is needed (8).  
 
1.2.3 
Inclusion criteria 
Inclusion criteria: 
- 
Patients on the waiting list for primary THA between 1-4-2020 up to 31-3-2022 in OLVG or 
Martini hospital. 
- 
Completed intake questionnaire (HOOS-PS baseline) 
- 
Indication osteoarthritis of the hip 
 
1.2.4 
Exclusion criteria 
Exclusion criteria:  
- 
Patients that received THA on both sides within follow-up (1-4-2020 and 1-1-2022) will be 
excluded.  
- 
Patients with other indications than osteoarthritis of the hip were excluded.  
1.2.5 
Number of subjects/ sample size 
Since we use observational data for trial emulation no sample size calculation is needed (8). The 
participants are already exposed to an intervention or not.  Differences in the primary and secondary 
outcomes (PROMs) between groups will be interpreted using 95% confidence intervals and thresholds 
for clinical relevance which are reported below. 
1.3 Data collection: variables and measurement methods 
1.3.1 
Primary outcome measure (dependent variable) 
Primary outcome is the change score for hip function measured with the HOOS-PS at 3-months 
postoperative in the THA group and at least 3-months post waiting list in the control group compared to 
baseline. The HOOS-PS is a 5-item questionnaire that quantifies hip disability. The raw outcome is 
converted to a Rasch-based interval score ranging from no difficulty (0) to extreme difficulty (100) (3,4,5). 
The minimal clinically important difference (MCID) for the HOOS-PS is 23 points (6). We will also calculate 
the minimal important change in our study population, based on an anchor question. 
3.5.2. Secondary outcome measure 
Secondary outcomes are change scores on other patient reported outcome measures (PROMs). Pain 
during weight bearing is measured on a numerical rating scale (NRS) ranging from 0-10. The minimal 
clinically important difference (MCID) for the NRS is 2 points. The anchor based questions range from 1-7 
for functioning and pain. These PROMs were obtained at baseline (except the anchor based question) 
and at 3-months postoperatively and at least 3-months post waiting list  
 
1.3.2 
Overview of variables and measurement instruments 

 
 
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Variable 
Measuring 
instrument/ 
Source of data 
Outcome values 
Measurement 
time 
Sex 
VBHC data 
(source is EHR*) 
numeric (1 = F, 2 = M) 
999 or NA is missing 
Baseline 
 
Age at time of inclusion 
VBHC data 
(source is EHR*) 
Numeric  
999 or NA is missing 
Baseline 
 
Date for order THA 
 
VBHC data 
(source is EHR*) 
date (YYYY-MM-DD) 
 
Baseline 
 
Surgery date 
 
VBHC data 
(source is EHR*) 
date (YYYY-MM-DD) 
or not applicable (NA) 
Date of surgery 
 
Date completion of baseline 
questionnaire 
VBHC data 
(source is EHR*) 
date (YYYY-MM-DD) 
 
Baseline 
 
HOOS_PS_BL 
HOOS_PS_PI 
VBHC data 
(source is EHR*) 
HOOS-PS personal 
interval level score at 
baseline. 
Numeric (0-100)  
999 or NA is missing 
Baseline 
 
Pain weight bearing at baseline 
NRS 
VBHC data 
(source is EHR*) 
numeric (0-10) 
999 or NA is missing 
 
Baseline 
 
 
Patient followed physical 
therapy before hospital visit 
VBHC data 
(source is EHR*) 
No (0) / Yes (1) 
999 or NA is missing 
 
Baseline 
 
Date completion of 3-months 
postoperative questionnaire 
VBHC data 
(source is EHR*) 
date (YYYY-MM-DD) 
or not applicable (NA) 
3-months PO 
Date completion of 3-months 
waiting list questionnaire 
VBHC data 
(source is EHR*) 
date (YYYY-MM-DD) 
or not applicable (NA 
≥ 3-months 
waiting list 
HOOS_PS_3M_PO 
HOOS_PS_PI 
VBHC data 
(source is EHR*) 
HOOS-PS personal 
interval level score at 3-
months postoperatively. 
Numeric (0-100)  
999 or NA is missing 
3-months PO 
HOOS_PS_3M_WL 
HOOS_PS_PI 
Waiting list 
questionnaire 
(source is EHR*) 
HOOS-PS personal 
interval level score at 3-
months waiting list. 
Numeric (0-100)  
999 or NA is missing 
≥ 3-months 
waiting list 

 
 
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Pain weight bearing at 3-months 
postoperatively 
NRS 
VBHC data 
(source is EHR*) 
numeric (0-10) 
999 or NA is missing 
 
 
3-months PO 
 
Pain weight bearing at 3-months 
waiting list 
NRS 
VBHC data 
(source is EHR*) 
numeric (0-10) 
999 or NA is missing 
 
 
≥ 3-months 
waiting list  
Anchor based question for pain 
postoperatively 
Anchor 
Numeric (1-7)  
1= very much 
deteriorated 
2= much deteriorated 
3= slightly worsened 
4= not changed 
5= slightly improved 
6= much improved 
7= very much improved 
999 = missing value 
3-months PO 
 
Anchor based question for 
function postoperatively 
Anchor 
Numeric (1-7)  
1= very much 
deteriorated 
2= much deteriorated 
3= slightly worsened 
4= not changed 
5= slightly improved 
6= much improved 
7= very much improved 
999 = missing value 
3-months PO 
 
Anchor based question for pain 
waiting list 
Anchor 
Numeric (1-7)  
1= very much 
deteriorated 
2= much deteriorated 
3= slightly worsened 
4= not changed 
5= slightly improved 
6= much improved 
7= very much improved 
999 = missing value 
≥ 3-months 
waiting list 
 
Anchor based question for 
function waiting list 
Anchor 
Numeric (1-7)  
1= very much 
deteriorated 
2= much deteriorated 
3= slightly worsened 
4= not changed 
5= slightly improved 
6= much improved 
7= very much improved 
999 = missing value 
≥ 3-months 
waiting list 
 
 
EHR = Electronic health record. 
 
NRS = Numerical rating scale 
 
PO = postoperatively 

 
 
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1.4 Data analysis 
 
1.4.1 
Data inspection 
Missing data will be defined in the database as 9999 or NA. Patients with a missing baseline HOOS-PS will 
not be included in the database. Extreme values will be explored by visual inspection such as boxplots 
and scatterplots. Extreme values will be verified and discussed in the research team before starting the 
analysis.  
 
1.4.2 
Analyses 
 
1. Measure if THA is effective to improve physical function in patients with osteoarthritis of the hip 
compared to non-surgery by means of RCT Target Trial Emulation.  
 
2. Assessment to test the assumption that group allocation to the surgery group or non-surgery 
group cannot be explained by patient characteristics by means of logistic regression analysis. 
Secondly we test the assumption that follow-up time in days is similar between the two groups.  
 
1. Measure effect of THA: 
Two multiple regression analyses will be performed with the HOOS-PS and pain change score, 
respectively, as the dependent variable, and experimental condition (THA/ no-THA), age, sex, HOOS-PS 
score at baseline, pain score at baseline, physical therapy before baseline (yes/no) and follow-up time in 
days as independent variables. All regression coefficients and their 95% confidence intervals will be 
provided. Differences will be considered statistically significant when p≤0.05 and clinically relevant when 
differences exceed the MCID of 23 points for the HOOS-PS and 2 points for the NRS (6,7). 
 
Descriptives on all independent variables will be presented and assessed by visual inspection of boxplots 
(for continuous variables) or tables (for categorical variables). These results will be provided for 
transparency purposes.  
 
 
2. Test whether assumptions for target trial emulation are met.  
A logistic regression analysis will be performed on patients within the VBHC data set between 1-4-2020 
and 1-1-2022 to check whether the group allocation cannot be explained by patient characteristics. 
Group being the dependent variable (THA vs. non-surgery) and age (continuous), sex (M/F), physical 
therapy before the hospital visit (yes/no), follow-up time in days (continuous), pain at baseline (NRS, 
continuous) and the HOOS-PS at baseline (continuous) will be included in the model as independent 
variables. Results will be considered statistically significant when p≤0.05. In case an independent variable 
has a statistically significant effect on the outcome, clinical relevance will be considered and discussed 
for the effect size on chance to be allocated to the THA or non-surgery group. Secondly, we will test the 
assumption that follow-up time in days is not statistically significantly different between the THA and 
non-surgery group.  Follow-up time is defined by calculating the number of days between the date of the 
orthopedic visit) and the date of the follow-up questionnaire. 
 
1.4.3 
Software program 
Data analysis: SPSS, R  
Data collection: SAS Enterprise guide and Questmanager 
2. ETHICAL CONSIDERATIONS 

 
 
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2.1 Burden and compensation for the test subject 
There is no additional investment required for patients, all data has already been collected.  
2.2 Subject consent  
In prospective non-WMO research, consent must always be sought from the subject. In the case of retrospective non-
WMO research, this depends on the method of data collection and its processing. If in doubt, you can use the decision 
tree in appendix A.  
Is consent sought from the 
subject? 
☐ 
 Yes (Complete option A 'Informed Consent Procedure') 
☒ 
No (Enter option B 'Consent is not requested') 
Option A: Informed Consent procedure  
 
Approach to subjects 
Not applicable 
 
Informing subjects 
Not applicable 
 
Reflection period for 
subjects 
Not applicable 
 
Signing informed consent 
Not applicable 
  
 
Option B: Consent is not asked, data is anonymized. 
 
Which exception rule(s) is/are applicable? Explain your answer at the bottom of this question. 
 
Note:  
For retrospective studies, where data from subjects are used anonymously, asking permission is not 
necessary.  
 
For retrospective research, where data from subjects are collected and processed in coded form, 
consent of the subjects is required. Patients should be informed which personal data (no more than 
necessary) will be processed in what way and for what purposes. In some cases, asking for consent may 
be waived (exception rules). These exception rules can only be invoked if the study meets the following 
conditions: 
- 
the research serves the public interest; and 
- 
the research is meaningful and clear and cannot be conducted without the requested data; and 
- 
the person did not object; and 
- 
with regard to the conduct of the investigation, safeguards are in place such that the privacy of 
those whose data is affected is not disproportionately affected. 
 
☐ 
Consent may not be required.  
This applies when asking for consent would take a disproportionate amount of time and effort, 
for example in the case of large numbers of patients or patients who were treated a long time 
ago. 
☐ 
Requesting consent is not reasonably possible, as asking consent would place such a 
burden on the patient that psychological harm must be feared. 

 
 
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☐ 
Requesting consent is not reasonably possible because the data subject is deceased or 
the address cannot be traced or if the data subject does not respond after being written 
to at least twice. 
☐ 
Asking for consent is not reasonably possible because it involves drawing the right 
sample and asking for consent would have to be presented to many more people than 
necessary to answer the research questions. 
☐ 
Requesting consent is not reasonably possible, as the consent question cannot be 
meaningfully asked because the study is still in an initial preparation phase. 
Research data will be collected and used anonymously. Consent from subjects is therefore not 
required. 
 
 
3. DATA MANAGEMENT & PRIVACY 
3.1 Data storage, security and access during research 
Paper research data 
3.1.1 
Where are paper research data (e.g. paper questionnaires and consent forms) stored? 
 
☒ 
N/A go to question 5.1.4 
3.1.2 
Which persons have access to this storage area? 
This should be at least two people because of access to the data in case of absence, illness, 
leaving the institution, etc. when only one person has access. 
 
<Note here the name and position of these persons.> 
 
 
3.1.3 
How is it ensured that no one other than the authorized persons mentioned under 5.1.2 
has access to the paper research data? 
 
<For example, describe where the key to the locked cabinet is kept or who knows the code of the safe.> 
 
Digital research data 
3.1.4 
In which system will the research data be collected and managed? 
 
☐ 
GCP-proof ECRF ( mandatory), such as: Castor EDC / Research Manager / Redcap, Open 
Clinica, other, namely <...> 
 
 
 
 
☒ 
Other, namely No new patient data will be collected. Already available and coded 
patient data will be retrieved using SAS Enterprise guide and analyzed using R and SPSS.  

 
 
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3.1.5 
Is (also) digital research data stored on a network drive of the participating hospitals ? 
Note, this should not be traceable data (key). These should always be stored in the hospital 
where they are collected (see also question 5.2.3.).  
 
☒ 
Yes, namely on the network drive of the following hospital: OLVG, secure network drive 
of JointResearch. 
☐ 
No, the digital research data will be stored at <location>.    
3.2 Data processing 
3.2.1 
Will research data be anonymized or coded? 
 
☒ 
Anonymized Go to question 5.2.4 
☐ 
Coded 
3.2.2 
How will the data be encrypted? 
N/A 
 
3.2.3 
Where is the trial subject identification code list (key between coded and patient traceable 
data) stored? 
 
 
 
☒ 
At a location of the participating hospitals namely: N/A 
☐ 
External. For external storage of the key including access authorizations, permission is 
requested from the patient in the patient information form (PIF). 
<Institution and department external> 
 
 
3.2.4 
By whom will the required data be extracted from the EHR and anonymized or encrypted? 
☐ 
Handler, namely:       
☒ 
support research staff, namely: the data analyst involved in VBHC through the data 
warehouse. 
☐ 
Business intelligence department (via data warehouse or Business Intelligence)  
☐ 
A third, namely:       
 
 
 
 
3.3 Sharing data 

 
 
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3.3.1 
Will research data be shared with third parties?  
 
☒ 
Yes, anonymized proceed to question 5.3.2 
☐ 
Yes, coded continue to question 5.3.2 
☐ 
No continue to question 5.4 
 
 
3.3.2 
To whom is the data provided / who uses the data for scientific research?  
 
☒ 
Institutions/researchers within the Netherlands, namely: OLVG hospital, Amsterdam, 
Orthopedic research department 
☐ 
Institutions/researchers within the European Union (EU), namely: <Note here the name 
and location of the institution(s).> 
☐ 
Institutions/researchers outside the EU, namely: <Note here the name and location of 
the institution(s)>. 
Note: For the provision of encrypted data outside the EU, patient consent should be 
sought via the patient information form (PIF).  
3.4 How long will the data be kept? 
15 years.  
4. Valorization and PUBLICATION 
4.1 Valorization 
Our hypothesis is that for patients with hip osteoarthritis, getting total hip replacement is an effective 
treatment compared to not operating. Demonstrating the importance of this surgery may change 
healthcare practice by generating more priority and resources (such as surgery time) within hospitals and 
society for treatment with total hip replacement.   
 
Using a relatively new research design (target trial emulation) can change research practice. Because 
randomized trials are time-consuming and costly, as well as having other potential drawbacks, 
alternative research designs are increasingly being considered. Participation in a randomized trial is also 
quite an investment for the patient. Therefore, being able to use alternative research methods to 
evaluate a treatment method also has a great benefit for the patient group. 
 
4.2 Publication 
The results will be submitted for publication to (inter)national peer-reviewed journal. The results will be 
presented to the orthopedics departments of the Santeon hospitals. Possibly, the results will be 
submitted for conference presentations. 
 
5. REFERENCES 
 
1. Groenwold RHH. Trial Emulation and Real-World Evidence. JAMA Netw Open. 2021 Mar 
1;4(3):e213845. doi: 10.1001/jamanetworkopen.2021.3845. 

 
 
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Version Santeon management committee 2.1 23 March 2020 
 
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