Clinical Trial Details
— Status: Recruiting
Administrative data
| NCT number |
NCT05690347 |
| Other study ID # |
10320052010006 |
| Secondary ID |
|
| Status |
Recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
January 1, 2022 |
| Est. completion date |
July 1, 2025 |
Study information
| Verified date |
January 2023 |
| Source |
Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA) |
| Contact |
daniel strijbos, PhD student |
| Phone |
+31622202362 |
| Email |
d.o.strijbos[@]amsterdamumc.nl |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Background Optimizing return to work (RTW) after knee arthroplasty (KA) is becoming
increasingly important due to a growing incidence of KA and poor RTW outcomes after KA. We
developed the Back At work After Surgery (BAAS) clinical pathway for optimized RTW after KA.
Since the effectiveness and cost analysis of the BAAS clinical pathway are still unknown,
analysis on effectiveness and costs of BAAS is imperative.
Method This protocol paper has been written in line with the standards of Standard Protocol
Items: Recommendations for Interventional Trails. To assess the effectiveness and
cost-effectiveness for RTW, we will perform a multicenter prospective cohort study with
patients who decided to receive a total KA (TKA) or an unicompartmental KA (UKA). To evaluate
the effectiveness of BAAS regarding RTW, a comparison to usual care will be made using
individual patient data on RTW from prospectively performed cohort studies in the
Netherlands.
Discussion One of the strengths of this study is that the feasibility for the BAAS clinical
pathway was tested at first hand. Also, we will use validated questionnaires and functional
tests to assess the patient's recovery using robust outcomes. Moreover, the intervention was
performed in two hospitals serving the targeted patient group and to reduce selection bias
and improve generalizability. The limitations of this study protocol are that the lead author
has an active role as a medical case manager (MCM) in one of the hospitals. Additionally, we
will use the data from other prospective Dutch cohort studies to compare our findings
regarding RTW to usual care. Since we will not perform an RCT, we will use propensity
analysis to reduce the bias due to possible differences between these cohorts.
Description:
Background Optimizing return to work (RTW) after knee arthroplasty (KA) is becoming
increasingly important due to the growing incidence of KA and poor RTW outcomes after
arthroplasty. The incidence of KA is predicted to rise substantially in the coming decades in
countries with established market economies (1-4). The largest increase is expected among
patients of working age (5). For instance, in 2030 the United States of America will be the
first country where the majority of patients getting KA are of working age, followed by Great
Britain in 2035 (3, 4). Although outcomes regarding pain relief and improved knee function
after KA are satisfactory, RTW among patients getting KA is relatively low. Prospectively
reported non-RTW rates are 33% within six months after KA and 13% within 12 months in the
Netherlands (6). Also, the economic burden of knee osteoarthritis in the Netherlands is high.
The average annual cost for the Dutch workforce due to sick leave for knee osteoarthritis was
26.9 million euros between 2015 and 2017 (7). Considering the increase in the demand from
patients seeking KA, the low RTW outcomes after KA, and a high economic burden, care
optimization for patients getting KA with a focus on RTW is essential.
A closer collaboration between professionals in medical care (e.g. orthopedic surgeon,
physical therapist) and occupational care (e.g. occupational physician) for working-age
patients with KA might improve their RTW probabilities after surgery (8). From the patient
perspective, an individual tailored, integrated (health care and work-directed),
comprehensive (from pre-operative to RTW) clinical pathway should preferably include
integrated and coordinated care from four domains: (i) rehabilitation (e.g. physical
therapy); (ii) patient support (e.g. setting proper goals); (iii) occupational support (e.g.
proper build-up modified work); and (iv) medical support (e.g. more personal guidance from
the hospital) (9, 10). Unfortunately, proven effective work-directed care is currently not
available for patients receiving KA (11, 12).
Recently, an integrated clinical pathway called Back At work After Surgery (BAAS) was
started, aiming to improve RTW after KA. BAAS was proven feasible in 2021 in practice
(appendix I) (13). The development of this care pathway was based on two pillars (14). The
first pillar was a timely combination of medical and occupational care, and the second pillar
was enhancing patient participation during the clinical pathway. In this way,
interdisciplinary communication was improved by making RTW an explicit outcome of the
rehabilitation, which might accelerate both rehabilitation and RTW. The next step is to
analyze the effectiveness and costs of the BAAS clinical pathway to RTW.
To the best of our knowledge, this is the first study on work-directed and patient-centered
care after KA systematically involving health care experts other than an orthopedic surgeon
and a physical therapist. Timely involvement of occupational care experts seems to be an
important evidence-based prerequisite to ensure that the BAAS clinical pathway can be more
effective on RTW after KA than usual care (6, 13, 15). However, since the true effectiveness
and costs or benefits of the BAAS clinical pathway are still unknown, analysis on
effectiveness and economic evaluation of BAAS is expedient. Our hypotheses are that an
integrated clinical pathway with a focus on RTW after KA is more effective on RTW than usual
care, and has a positive economic evaluation.
This multicenter study has two aims. Firstly, to assess the effectiveness of the BAAS
clinical pathway for RTW compared to usual care. Secondly, to evaluate the economics of the
BAAS clinical pathway compared to usual care. This paper describes the study protocol for the
multicenter study.
Methods Study design This protocol paper has been written in line with the standards of
Standard Protocol Items: Recommendations for Interventional Trails (SPIRIT) (16). We will
perform a multicenter prospective cohort study with patients who have decided to be given a
total KA (TKA) or a unicompartmental KA (UKA). To establish generalizability, the BAAS
pathway will be performed in two high-volume KA hospitals in the Netherlands serving a
representative population of working patients receiving KA. For the effectiveness of BAAS
regarding RTW, the results of the study will be matched in pairs and compared to individual
patient data on RTW by matched pairs from prospectively performed cohort studies in the
Netherlands on care as usual, namely the Expect to Work cohort and the ACTIVE trial (17, 18).
For the economic evaluation, a comparison will be made with individual patient-level data
using the care-as-usual group of the ACTIVE trial in the Netherlands (17). The study has been
approved by the Medical Ethical Committee of the Amsterdam UMC, location AMC (reference ID:
W21_454 # 21.504) and the Medical Ethical Committees of the local hospitals Nij Smellinghe
(NS, reference ID: 19888) and Elizabeth Tweesteden Ziekenhuis (ETZ, reference ID: L1429.2021)
Study setting This study will take place in two hospitals in the Netherlands. The first is
Nij Smellinghe (NS) hospital located in Drachten, in the northern part of the Netherlands. NS
has approximately 320 clinical beds and three orthopedic surgeons who perform approximately
350 KAs a year. The second is the Elizabeth Tweesteden Ziekenhuis (ETZ), a larger regional
hospital located in Tilburg, in the southern part of the Netherlands. ETZ has 940 beds and 6
orthopedic surgeons who perform approximately 700 KAs a year.
Participants Sample size A minimal required sample size was calculated using R (version
3.6.3) with a power of 0.8 and a significance level of 0.05. The effect size was calculated
with a mean difference of two weeks in comparison to a Dutch study on RTW after KA (15). With
a calculated minimal required sample size of 125 and an expected loss to follow-up of 20%, we
intend to include 150 patients (75 in NS and 75 in ETZ).
Recruitment Inclusion criteria for patients are: (ii) being scheduled for primary or revision
UKA or TKA by an orthopedic surgeon between January 2022 and July 2023; (ii) having paid work
for at least eight hours a week before surgery; (iii) being between 18 and 65 years of age
and (iv) having the intention to fully RTW after surgery. Criteria to exclude patients are:
(i) receiving more than one medical event within one year that affects work ability after KA;
(ii) having a KA for any other reason than knee osteoarthritis; and (iii) having major
disabling mental disorders. Patients who do not speak or read Dutch are given the opportunity
to fill in the questionnaires with the aid of a translator and to have an interpreter present
during the consultations. Patients who are eligible to participate are informed about the
study by telephone by the medical case manager (MCM; physical therapist working in the
hospital). During an intake consultation with an MCM, the patient information letter,
informed consent, and an infographic of the BAAS clinical pathway (Appendix I) are handed out
to the patient. Patients' questions regarding participation are answered. Patients are given
one week to decide whether or not they wish to participate. Patients who opted for the
possibility to participate receive a telephone call after one week so that they can ask any
additional questions about the study and they will be asked if they want to participate.
Participants willing to participate sign the informed consent.
Patient timeline Since the analysis on effectiveness and economic evaluation will be
conducted on the same cohort, the participant timeline will be identical (Fig. 1 and Table
1).
Measures Primary outcomes For the study on effectiveness, the primary outcomes are first day
of RTW and/or first day of full RTW. First day of RTW is defined as: time in days from
surgery to the first day of returning to work, regardless of the number of working hours or
tasks performed. Full RTW is defined as: time in days from surgery to the first day a patient
works the number of hours stated in his or her employment contract regardless of the tasks
performed. For self-employed patients, full RTW is defined as: the first day of the week a
patient works the number of hours equal to the number of hours he or she worked before
surgery. For the first days to RTW the prospective Expect to Work study by Van Zaanen et al.
will be used as usual care cohort, and for full RTW the ACTIVE trial comparison group by
Straat et al. will be used (17, 18). Test-retest reliability, minimal clinical importance
difference, and minimal detectable difference of self-reported RTW are not described in the
medical literature, if we are not mistaken. The effectiveness study of BAAS will be reported
according to the Strengthening the Reporting of Observational Studies in Epidemiology
(STROBE) guidelines (19).
For the economic evaluation, the primary outcomes are the total costs of the intervention,
and the societal and health care cost obtained by a cost-questionnaire at 3, 6, 9 and 12
months according to the guidelines of the Dutch Health Care Institute (Zorginstituut
Nederland), in line with the study performed by Straat et al. (17, 20). The economic
evaluation will be reported according to the Consolidated Health Economic Reporting Standards
2022 (CHEERS 2022) and we will use the human-capital method (21).
Costs of the BAAS care pathway intervention include: (i) cost of case managers; (ii) cost of
compiling the report by the OCM; (iii) cost of professionals present at the digital
interdisciplinary consultation and (iv) cost of the use of the accelerometer program. These
costs will be estimated using the micro-costing approach. In other words, the cost estimation
will be based on actual resources depleted, which will be assessed using prospective data
collection, and will be valued in accordance with the Dutch guidelines for conducting
economic evaluations in health care (20). Societal cost includes occupational health care
services, informal care, unpaid productivity loss, absenteeism, presenteeism and other health
care services. Absenteeism (e.g. total number of sick leave days, measured prospectively by
the MCM) and presenteeism (e.g. lower productivity as compared to normal while at work) will
be valued using sex-specific price weights (20). Unpaid productivity losses (e.g. voluntary
work) and informal care are measured by asking the number of hours per week patients were
unable to perform unpaid activities in the cost-questionnaire. Unpaid productivity losses and
informal care will be valued using a recommended Dutch shadow price (20). Using consumer
price indices, all costs will be converted to the same reference year by using the
human-capital method.
For health care costs, all costs according to the formal Dutch health care sector will be
obtained, including cost of primary care (e.g. family physician or primary care physical
therapist), secondary care (e.g. hospital stays and visits), tertiary care (vocational
rehabilitation) and medication. If available, these will be valued using Dutch standard costs
(20). If unavailable, prices of professional health care organizations will be used.
Medication use will be valued using prices derived from http://www.medicijnkosten.nl. All
costs will be summed and divided by the number of participants, separate for both groups.
This will lead to average (95% CI) total costs per participant.
Secondary measures The Work, Osteoarthritis and Joint-Replacement Questionnaire (WORQ) is a
questionnaire containing thirteen 0-4-scale questions regarding perceived difficulty with
performing work-related knee straining activities, calculated to a 0-100 total score, in
which a higher score represents less difficulties performing the activity (22). The WORQ is a
reliable, valid, and responsive questionnaire that can be used to evaluate the impact of knee
complaints following KA on patients' ability to work with an inter rater correlation (ICC) of
0.97 (22).
The Knee Injury and Osteoarthritis Outcome Score (KOOS) is a questionnaire containing
thirty-seven 0-4 ordered category questions regarding KA-related symptoms, pain, activities,
sport participation, and quality of life domains, normalized into a 0-100 total score on
every domain, in which a higher score represents less restriction on the given domain (23,
24). The KOOS demonstrates adequate content validity, internal consistency, test-retest
reliability, and construct validity with an ICC of 0.85-0.90 (25).
The Central Sensitization Inventory (CSI) is a questionnaire containing twenty-five 0-4-scale
questions regarding pain sensitization-related symptoms in which a higher score represents a
higher change on pain sensitization-related symptoms (26). The Dutch translation of the CSI
has four distinguishable domains, has good internal consistency for the total score and three
out of four domains, good discriminative power, and excellent test-retest reliability (26).
The Work Ability Score (WAS) consists of the worker's self-reported current work ability
compared to the lifetime best. The score ranges from 0 to 10 and a lower score represents a
lower ability to work (27). The WAS is more user-friendly than the Work Ability Index and has
a good and comparable reliability (28).
The iMTA Productivity Cost Questionnaire (iPCQ) is a questionnaire containing cost-related
questions regarding health and work (29, 30). Test-retest reliability, minimal clinical
importance difference, and minimal detectable difference of the iPCQ are unknown.
The de Morton Mobility Index (DEMMI) is a 15-item unidimensional mobility instrument that
measures static and dynamic balance. The 15 items are recalculated to a 0-100 points score,
in which a higher score represents better mobility (31). The DEMMI has a good validity, a
Minimal Detectable Change (90; MDC), and minimal clinical important difference (MCID) of
respectively 9 and 10 points (31).
The 6MWT is a walk test in which the maximum walking distance is measured during a period of
six minutes (32). The 6MWT has an MCID of 74.3 meters (33).
The 30-STST is an instrument to assess the functional status of patients. A patient is asked
to perform as many sit and stand repetitions within 30 seconds without using their hands. The
30-STST is a valid and reliable instrument and has an MCID of 1.13 (34).
The FTST is a similar test to the 30-STST and measures the time it takes for a patient to
perform 5 sit and stand repetitions without using their hands. Because of their similarity,
the 30-STST and FTST can be performed simultaneously. The FTST is a valid and reliable
instrument and has an MCID of 2.3 seconds (35).
The floor-to-waist lifting test is a reliable and valid performance-based test to assess a
patient's functional capacity (36, 37). Reference values to assess whether a patient is
restricted regarding functional capacity to RTW are between 16 and 24, dependent on the
physical nature of the job (38).
Demographics We will collect age, sex, length, weight, type of surgery (UKA/TKA), side of
surgery (left/right), length of stay, working hours per week, working days per week, physical
nature of the job, preoperative sick-leave days, breadwinner, being self-employed,
comorbidities, and complications after surgery.
Study intervention The following BAAS work-directed care is offered to the patient, which was
proven feasible (Appendix I) (13). The orthopedic surgeon provides information before surgery
about returning to work after surgery in terms of expected time to RTW and the known
prognostic factors like female gender, affirmative patient-reported work-relatedness of knee
symptoms, high physical work demands, high Body Mass Index (BMI), and prolonged preoperative
sick absence from work (39, 40). Next, the orthopedic surgeon refers the patient to the MCM
for a preoperative examination. During this preoperative examination, the patient fills out
several questionnaires (WORQ, KOOS, CSI, WAS and iPCQ; Table 1) so the MCM gains insight in
the preoperative status of the patient (Fig. 1). Then, the patient is subjected to
performance-based physical tests to evaluate the functional capacity, namely a floor-to-waist
lifting test and functionality tests, including the DEMMI, FTST, 30-STST, and 6MWT. During
this preoperative examination, the patient is given information about the perioperative care
and has the opportunity to ask questions about the recovery trajectory. The findings of the
preoperative examination are used as baseline measurements for setting goals in the
postoperative rehabilitation and as reference values for postoperative recovery. Next, the
patient receives an accelerometer (PAM 2.0), including the option of feedback from the
software application Atris (Peercode B.V.) during the preoperative examination. The movement
data is accessible for the patient, the primary care physical therapist, and the MCM. A week
later, the MCM calls the patient to discuss the current physical activity assessed by the
accelerometer and give advice on the preferred physical preoperative preparation. For
example, patients are advised to train functional movements required after surgery, such as
walking with a walking aid, or are advised to maintain or increase the current physical
fitness level by adhering to the WHO's latest physical activity guideline (41). The MCM then
contacts the occupational physician to inform him or her about the participation of the
patient in this clinical pathway. The patient is advised to consult the occupational
physician before surgery. Then, the patient is referred to the occupational case manager
(OCM; occupational assessor) by the MCM, to compile a report of beneficial and limiting
factors regarding RTW after KA.
During the hospitalization, the patient receives perioperative care as usual according to the
KA fast track principles in both hospitals (42). At NS hospital, patients who have decided to
have KA receive an Oxford uncemented Partial Knee (Zimmer Biomet), NexGen® LPS-Flex or CR
Total KA (Zimmer Biomet) or Medial Rotation Knee total knee replacement (BdH Medical BV) or
SAIPH® Knee System (BdH Medical BV). At ETZ hospital, patients who have decided to have KA
receive a SIGMA® Total Knee System (Johnson and Johnson) or an Oxford Partial Knee (Zimmer
Biomet).
In both hospitals, patients will receive physical therapy according to usual care while being
hospitalized for two or three times a day, with the goal of gaining independence in
activities of daily living such as walking, transfers in and out of bed or chair, and walking
up and down stairs if necessary (43). Also, the orthopedic surgeon and physical therapist
motivate the patient to train range of motion of the knee to at least full extension (0
degrees) and 90 degrees of flexion. After hospitalization, the patient receives physical
therapy from a primary physical therapy setting according to the patient's preferences and
taking into account the Royal Dutch Society for Physiotherapy (KNGF) guidelines for knee
osteoarthritis (44). The physical therapist is informed that the patient is participating in
BAAS care pathway, and informed about the content of this pathway through an information
letter. A work-related therapy goal is set up from the start of the therapy and monitored
every six weeks throughout the whole clinical care pathway using Goal Attainment Scaling
(GAS, Fig. 1) by the MCM. Progress in recovery is evaluated through questionnaires (WORQ,
KOOS, and CSI), functional capacity test (floor-to-waist lifting test), functional tests
(DEMMI, FTST, and 6MWT) and the physical activity level measured by the accelerometer (Table
1). The questionnaires and functional capacity evaluations tests are repeated at 6 weeks and
every 3 months after surgery (Fig. 1), with the exception of the floor-to-waist lifting test
at six weeks after surgery due to patient safety reasons. Data from the accelerometer is
evaluated by the MCM on a weekly basis. Stop criteria for the BAAS clinical pathway are full
RTW or, if RTW was not achieved after one year.
An interdisciplinary consultation is held the fourth or fifth week after surgery. The
patient, the primary care physical therapist, the MCM, OCM, and occupational physician are
invited to participate (Fig. 1). During this consultation, the progress, the attainment of
the GAS goal, and RTW plan according to the Dutch Gatekeeper Improvement Act are discussed.
If the patient has a job which he or she probably cannot return to, for example because of
high knee demands due to prolonged kneeling and squatting, the possibility of work adaptions
or even the topic of finding a less physically strenuous job are discussed (Fig. 1). The
interdisciplinary consultation is continued if required, for instance based on unfavorable
recovery data. If, after three months a delayed recovery is seen based on the patient's
experience and expert opinions of the MCM, OCM, and occupational physician, and supported by
questionnaires, functional capacity evaluations and accelerometer data, the patient is
referred to a multidisciplinary rehabilitation assessment (Fig. 1). Here, the patient is
examined by a rehabilitation physician, occupational medicine specialist, physical therapist,
and psychologist to assess barriers for delayed recovery and RTW, and whether the patient is
eligible for an interdisciplinary vocational rehabilitation program. If so, the patient
receives this interdisciplinary rehabilitation program (45).
The MCM from NS hospital, who is experienced in fulfilling the task of MCM through the
previously performed feasibility study, will train two physical therapists working in ETZ.
These physical therapists perform the tasks of an MCM in their hospital. Also, the MCMs of
ETZ will be trained to perform all functional tests. Every two weeks a digital consultation
will be held between all MCMs to discuss progress of the study and any questions that have
arisen during the entire study period.
Data collection For the effectiveness study, both date of surgery and RTW data are collected
by the MCM. In addition to the RTW data, the preoperative data and health surveillance data
(Fig. 1) are collected in the same file by the same MCM.
Data management For this study, data will be coded and collected in a password-protected
Microsoft Excel file. A separate Excel file will refer to the coded data of individual
patients that is only accessible by the MCM.
Statistical methods Effectiveness The effect of the BAAS care pathway on time to RTW will be
statistically tested using survival analysis and gamma regression analysis including
bootstrapping using R (version 4.1.0). Missing data will be handled by multivariate
imputation using the aforementioned prognostic factors if possible (46). For the repeated
measurements on the time to RTW and/or full RTW, a mixed model will be used to test and
estimate the size of the BAAS effect controlling for the following potential prognostic
factors of delayed RTW, namely UKA vs TKA, primary vs revision KA, gender, BMI, physical
nature of the job, preoperative sick leave, and patient-reported work-relatedness of knee
symptoms. Hazard ratios including 95% confidence intervals will be calculated for the
intervention group and tested against both control groups. In the absence of an empirically
derived MCID, a difference of two weeks will be considered clinically relevant for first day
of RTW and one week for full RTW. For interpreting the magnitude of the standard mean
difference (SMD), three groups are defined: (i) small (SMD = 0-0.2); (ii) medium (SMD =
0.2-0.5) and (iii) large (SMD = 0.5-1.0) (47). Sensitivity analyses on RTW will be performed
for the two hospitals. Analyses will be conducted using both univariate and multivariate
analyses to assess the effect size of the BAAS care pathway with and without controlling for
variables. Lastly, because this control group is not from the same cohort as the intervention
group, we will use propensity analysis (matched pairs) to correct for other confounding
factors (48). Potential prognostic factors for delayed RTW like UKA vs TKA gender, BMI,
physical nature of the job, preoperative sick leave and patient-reported work-relatedness of
knee symptoms will be used for patient matching. Secondary outcomes will be plotted in time
and will be tested on differences between the usual care cohorts and the intervention cohort.
Economic evaluation For the economic evaluation, missing data will be imputed using
multivariate imputation using the aforementioned prognostic factors if possible (46). An
Ordinary Least Squares regression model with bootstrapping will be used to investigate the
differences between the BAAS cohort and the usual care cohort of the ACTIVE trial. Lastly,
because this control group is not from the same cohort as the intervention group, we will use
propensity analysis to correct for the two different cohorts (intervention and control) (48).
Potential prognostic factors for delayed RTW like UKA vs TKA gender, BMI, physical nature of
the job, preoperative sick leave, and patient-reported work-relatedness of knee symptoms will
be used for patient matching. Results will be plotted for interpretation. The difference in
costs and benefits are clinically relevant when the intervention has more financial benefit
in comparison with usual care.
Discussion This study describes the protocol to evaluate the effectiveness of the BAAS care
pathway for RTW as well as its costs and benefits. To the best of our knowledge, this is the
first work-directed and patient-centered care after KA systematically involving health care
experts other than an orthopedic surgeon and a physical therapist.
To the best of our knowledge, there is no previous study concerning minimal clinical
differences in return to work after surgery. Therefore, we held a consensus meeting with
authors DS, GS, TB, PK and MR in which we concluded that a minimal clinical difference of two
weeks on start to return to work and one week for full return to work is relevant.
Until now, no core outcome set exists for work participation including RTW to be used in
intervention studies (49, 50). Previous studies on RTW among patients with knee arthroplasty
defined RTW in different ways. For example, Hylkema et al. measured the proportion of full
RTW within 3, 6 or 12 months by asking the patient via a questionnaire whether they partially
or fully returned to work, or not at all (6). Tilbury et al. measured RTW by asking patients
through a follow-up questionnaire what the duration from operation until the first day of RTW
was (15). Systematic reviews on RTW among patients with knee arthroplasty concluded that
pooling data on RTW results in heterogeneity due to these varying RTW outcomes. To obtain a
valid comparison, we used the same RTW definitions as those used in the prospective studies
of Straat et al. and Zaanen et al. (17, 18). While this RTW definition is needed to compare
the results with the prospective studies, it also means that comparisons with other studies
(vice versa) should be performed carefully.
The strengths of this protocol are that the BAAS clinical pathway was already proven feasible
(13). This way, not only did we learn that BAAS was feasible to implement, but we also
learned important lessons to optimize the BAAS clinical pathway before evaluating its
effectiveness, costs, and benefits. Also, the feasibility showed us promising results on the
first day of RTW and full RTW in comparison to other Dutch prospective studies on RTW after
KA. For example, patients started on average after 6.4 [6-8.1] weeks, in comparison to 12.9
weeks in the study of Tilbury et al. (15). Patients fully returned to work on average after
12.4 [9.4-14.4] weeks, in comparison to the study of Hylkema et al., where 49% of the
patients took more than six months to full RTW (6). Of course, the present study should show
whether these RTW data are reliable and valid. Also, we will use reliable and valid
questionnaires and functional tests to assess the patient's recovery. In addition, patients
who experience widespread sensitization after KA are identified early and can be referred for
multidisciplinary vocational rehabilitation (45, 51). Also, by setting personal goals
regarding work-related knee-straining activities using Goal Attainment Scaling, all the
involved professionals have a focus towards work participation (52). This probably supports
both patient and professional in a timely and better collaboration between professionals
within the medical and occupational trajectory. By focusing on these work-related activity
goals, we aim to create more awareness in the multidisciplinary team about the values and
needs of patients regarding their disability and what he or she is intended to achieve in
work.
In transition processes, in which care as usual is replaced by a new care pathway, the
essential role of the patients and health care professionals is often overlooked. Therefore,
in our study the professionals involved in the care transitions in the two hospitals will
collect and scrutinize the data together and, based on the results, determine what kind of
action should be performed to enhance RTW in close contact with the patient. One of the
consequences of this iterative cycle will be that all professionals as well as the patients
involved become partners in achieving an optimal RTW. This way, the embedded scientist who,
in daily practice, collects, creates, and reviews knowledge, and investigates the
effectiveness of this newly implemented care pathway is an essential actor in creating and
implementing future RTW pathways for other groups of working age patients.
Lastly, by using the data from two Dutch cohorts on RTW with similar inclusion criteria, our
study is designed to be more cost-effective than a randomized controlled trial.
The limitations of this study protocol are that the lead author has an active role as an MCM
in this study. This is why we included patients from a second hospital (ETZ). Also, we will
not perform an RCT. We will use the data from two other prospective cohort studies with
similar inclusion criteria to compare our findings to usual care. The care for knee
arthroplasty is, fortunately, largely standardized in the Netherlands (44, 53). Also, we will
use propensity analysis to reduce the bias due to possible differences between our cohorts
and the two comparison cohorts (17, 18).
