DOI : 10.
36803/indojpmr.
Indonesian Journal of Physical Medicine and Rehabilitation | Volume 14.
Issue 02, 2025
ORIGINAL ARTICLE
Analysis of the Quality-of-Life Domain in Knee Injury an Osteoarthritis Outcome Score as an Expansion of Western Ontario and McMaster Universities Osteoarthritis Index for Evaluating Knee Osteoarthritis Therapy Outcomes Agung Hidayatulloh1.
Gde Ganjar Oka Narasara2 AGeneral Practitioner.
RSI Sakinah Mojokerto.
Mojokerto.
Jawa Timur.
Indonesia APhysical Medicine and Rehabilitation Specialist.
RSI Sakinah Mojokerto.
Mojokerto.
Jawa Timur.
Indonesia
ABSTRACT
Introduction: Knee osteoarthritis is a degenerative joint disease-causing pain and functional limitation, with rising prevalence globally and in Indonesia.
Outcomes are commonly assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), which evaluates pain, stiffness, and function, but excludes quality of life (QOL).
Rehabilitation medicine emphasizes not only symptom relief but also recovery and life quality.
The Knee Injury and Osteoarthritis Outcome Score (KOOS) add a QOL domain for more comprehensive evaluation.
Method: A pre-post observational study was conducted on 24 knee osteoarthritis patients receiving ultrasound diathermy and transcutaneous electrical nerve stimulation (USD TENS).
KOOS scores for pain, activities of daily living (ADL), and QOL were recorded before and after intervention.
Paired t-tests or Wilcoxon tests analyzed score changes, while Pearson or Spearman tests assessed correlations between iQOL and ipain, iADL, and iWOMAC.
Result: KOOS scores improved significantly after therapy .
re = 58.
post = 33.
p < 0.
, including QOL .
= 0.
, pain .
re = 52.
post = 30.
p = 0.
, and ADL .
re = 58.
post = 37.
p = 0.
However.
QOL changes were not significantly correlated with ipain .
= 0.
p = 0.
, iADL (A = 0.
p = 0.
, or iWOMAC (A = 0.
p = 0.
Conclusion: The QOL domain in KOOS reflects a distinct dimension not captured by WOMAC.
KOOS thus offers a more holistic and patient-centered evaluation of therapeutic outcomes, highlighting the importance of including QOL in rehabilitation medicine.
Keywords: knee osteoarthritis.
KOOS.
WOMAC, quality of life.
USD TENS Correspondence Detail:
Agung Hidayatulloh General Practitioner.
RSI Sakinah Mojokerto.
Mojokerto.
Jawa Timur.
Indonesia Email: dr.
hiday92@gmail.
A Indonesian Journal of Physical Medicine and Rehabilitation Ai Published by PP PERDOSRI This is an open access article under the CC - BY .
ttp://creativecommons.
org/licenses/by/4.
0/).
184 Evaluating Knee Osteoarthritis Therapy Outcomes INTRODUCTION Knee osteoarthritis (KOA) is a degenerative joint disease characterized by progressive cartilage loss, pain, and functional limitation1.
Globally.
KOA is one of the leading causes of disability, with prevalence and disease burden increasing in the past decade1,2.
In Indonesia, the Global Burden of Disease (GBD) 2019 study reported that KOA prevalence more than doubled between 1990 and 2019, accompanied by rising incidence and years lived with Major risk factors include older age, female sex, obesity, prior joint injury, and genetic The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is among the most widely used instruments to evaluate KOA outcomes, assessing three domains: pain, stiffness, and physical function in activities of daily living (ADL)4,5.
While WOMAC is reliable, it does not include a quality of life (QOL) domain, limiting its ability to fully capture patient-centered outcomes4,5.
To address this limitation, the Knee Injury and Osteoarthritis Outcome Score (KOOS) was developed, incorporating all WOMAC items plus additional domains to capture broader patient KOOS comprises five domains: pain, other symptoms.
ADL, sport/recreation, and kneerelated QOL6,7.
By incorporating a QOL domain.
KOOS reflects the philosophy of rehabilitation medicine, which emphasizes holistic, patient-centered outcomes that integrate physical, psychological, and social dimensions of health .
,9,.
Given its broader scope.
KOOS is better positioned to evaluate the multidimensional impact of KOA and its treatment.
Ultrasound
(USD)
transcutaneous electrical nerve stimulation (TENS) are widely applied non-pharmacological modalities in KOA rehabilitation.
Both have shown efficacy in reducing pain, disability, and improving function and QOL when measured by WOMAC or generic instruments9,10.
Pain reduction is expected to improve activities of daily living (ADL), which in turn may enhance patients overall quality of life (QOL).
However, the strength of this relationship remains unclear in patients undergoing combined USD and TENS therapy.
Only few studies have evaluated their effects using KOOS, particularly the QOL domain, and the relationship between improvements in QOL and changes in pain or function remains underexplored8,11.
Hidayatulloh et al.
, 2025
Therefore, this study aimed to evaluate changes in KOOS, particularly the QOL domain, before and after combined USD and TENS therapy, and to examine correlations between QOL changes and changes in pain.
ADL, and WOMAC scores.
METHODS
Study Design and Setting This was a quasi-experimental preAepost study without a control group, conducted at the Physical Medicine and Rehabilitation Department.
RSI Sakinah Mojokerto.
East Java.
Indonesia, between March and June 2025 .
our month.
Participants A total of 24 consecutive patients with knee osteoarthritis were recruited from the outpatient rehabilitation clinic during the study period.
Patients who were clinically and radiologically diagnosed with knee osteoarthritis according to the American College of Rheumatology (ACR) criteria were invited to participate, completed baseline assessment, received therapy, and were reassessed after eight therapy Inclusion criteria were: .
age Ou 40 years, .
diagnosis of KOA according to ACR criteria, .
willingness to participate, and .
ability to complete the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire.
Exclusion criteria included:
knee surgery in the past 6 months, .
acute knee injury within the last 3 months, .
severe neurological deficits, and .
other musculoskeletal disorders affecting lower limb function.
A consecutive sampling approach was used, in which all eligible patients who presented during the study period and met the criteria were included.
No a priori sample size or statistical power calculation was performed, as the sample represents real-world clinical cases within a limited research time frame.
Ethical Considerations This study was reviewed and approved by the Research Ethics Committee of Universitas Pesantren Tinggi Darul Ulum Jombang (Approval No.
103-KEPUnipdu/02/2.
Written informed consent was obtained from all participants prior to data collection and treatment.
Indonesian Journal of Physical Medicine and Rehabilitation | Volume 14.
Issue 02, 2025 Intervention All participants received a combined therapy consisting of ultrasound diathermy (USD) and transcutaneous electrical nerve stimulation (TENS), administered two times per week for four consecutive weeks .
total of eight session.
The interventions were delivered by licensed physiotherapists under the supervision and prescription of a rehabilitation medicine specialist.
USD and TENS were applied to the affected knee region corresponding to the patientAos area of pain.
Specific device parameters .
requency, intensity, and pulse widt.
were not standardized, as treatment settings were adjusted according to the patientAos tolerance and clinical response, based on the supervising physicianAos clinical judgment.
Outcome Measures Patient-reported outcomes were assessed using KOOS, focusing on three domains: pain, activities of daily living (ADL), and quality of life (QOL).
For comparison.
WOMAC scores were derived from the KOOS pain and ADL subscales, which has been validated in previous studies (Ebrahimzadeh et al.
, 2015.
Paradowski et al.
, 2.
Measurements were taken before and after the The questionnaire was self-administered by each participant under the supervision of the principal investigator, who provided clarification when necessary and was responsible for scoring and data entry.
All KOOS and WOMAC domain scores were converted into percentage values (%) using the formula: .
btained score / maximum possible scor.
y 100%, with higher percentages indicating greater symptom severity .
% = maximum impairment.
= no impairmen.
We focused on pain.
ADL, and QOL domains, as these represent the most clinically relevant outcomes in rehabilitation and are most directly related to patients perceived quality of life.
Statistical Analysis Data were analyzed using SPSS version 22.
Normality was tested with the ShapiroAeWilk test.
For normally distributed variables, paired t-tests were otherwise, the Wilcoxon signed-rank test was applied.
Correlations between changes in QOL .
QOL) and changes in pain .
ADL .
ADL), and WOMAC .
WOMAC) were examined using PearsonAos correlation coefficient for normally distributed data and SpearmanAos rank correlation coefficient for non-normally distributed data.
All tests were two-tailed, and a p-value < 0.
05 was considered statistically significant.
RESULTS
Participant Characteristics A total of 24 patients with knee osteoarthritis participated in this study.
The demographic and clinical characteristics of the participants are summarized in Table 1.
The mean age was 59.
51 years .
ange: 46Ae75 year.
, and the majority were female .
%).
The mean height, weight, and BMI 46 A 6.
33 cm, 64.
33 A 7.
31 kg, and 26.
99 kg/mA, respectively, indicating that most participants were within the overweight category.
The affected side was bilateral in 45.
8%, right-sided in 7%, and left-sided in 12.
5% of participants.
Table 1.
Demographic and clinical characteristics of participants Variable Age .
Height .
Weight .
BMI .
g/mA) Sex (Female / Mal.
Affected side Mean A SD 17 A 8.
46 A 6.
33 A 7.
71 A 1.
n (%) Range Ai 46Ae75 145Ae165 52Ae78 %) / 6 .
Ai Right: 10 .
Ai Left: 3 .
Bilateral: 11 .
Values for continuous variables are presented as mean A standard deviation (SD), as all numerical data were normally distributed based on the ShapiroAeWilk normality test.
Categorical variables are presented as number .
A Indonesian Journal of Physical Medicine and Rehabilitation Ai Published by PP PERDOSRI This is an open access article under the CC -BY.
ttp://creativecommons.
org/licenses/by/4.
0/).
186 Evaluating Knee Osteoarthritis Therapy Outcomes KOOS and WOMAC Changes After USD
TENS
All KOOS and WOMAC scores were expressed as percentages (%) of maximum Hidayatulloh et al.
, 2025
impairment, with lower values indicating clinical A significant improvement was observed across all domains after four weeks of combined USD and TENS therapy (Table .
Table 2.
KOOS and WOMAC scores before and after intervention Domain Pre-intervention Post-intervention Mean A SD Mean A SD KOOS Pain 75 A 20.
83 A 14.
KOOS ADL
33 A 16.
75 A 11.
KOOS QOL
25 A 14.
21 A 14.
KOOS Total 69 A 14.
54 A 9.
(Pain ADL QOL) WOMAC Total 83 A 18.
96 A 10.
(Pain ADL) Test statistic p-value Z = Ae4.
= 8.
Z = Ae3.
= 11.
< 0.
< 0.
< 0.
Z = Ae4.
< 0.
Z values represent results of Wilcoxon signed-rank tests for non-normally distributed data.
t values represent results of paired ttests for normally distributed data.
A significance level of = 0.
05 was applied.
Correlation Between QOL Change and Other Domains Correlations between changes in QOL .
QOL) and other domains were analyzed using SpearmanAos or PearsonAos correlation coefficients, based on the normality of each dataset.
No significant correlations were found between iQOL and changes in pain.
ADL, or WOMAC scores.
The correlation results are summarized in Table 3.
Table 3.
Correlation between changes in quality of life .
QOL) and other outcome domains Domain comparison Test used Correlation coefficient p-value iQOL vs iPain Pearson r = 0.
iQOL vs iADL Spearman A = 0.
iQOL vs iWOMAC (Pain ADL) Spearman A = 0.
r values represent Pearson correlation coefficients for normally distributed data.
A values represent SpearmanAos rank correlation coefficients for non-normally distributed data.
DISCUSSION
This study found that Quality of Life (QOL) ultrasound diathermy (USD) and transcutaneous electrical nerve stimulation (TENS), but these improvements did not strongly correlate with reductions in pain or activities of daily living (ADL).
This suggests that QOL reflects broader psychosocial and functional perceptions beyond physical symptoms The novelty of this study lies in the use of the KOOS-QOL subscale, which specifically measures knee-related quality of life rather than general wellbeing.
Unlike broader instruments such as the SF-36 or WHOQOL-BREF, the KOOS-QOL domain captures patientsAo subjective perception of their knee function, symptoms, and confidence in daily activities.
To our knowledge, this is the first study in Indonesia to examine KOOS-QOL changes in response to USD TENS, highlighting its unique contribution to rehabilitation research.
KOOS was developed as an extension of WOMAC by adding the Quality of Life (QOL) domain as an important dimension previously absent in WOMAC, thereby providing a more comprehensive picture of the patientAos condition13.
Validation studies have shown that KOOS, including its QOL subscale, demonstrates good reliability and validity as a more comprehensive assessment tool compared to WOMAC, with the QOL domain capturing aspects distinct from physical function14.
When compared with previous studies, our findings align with evidence showing that both TENS and USD contribute to improvements in pain.
Indonesian Journal of Physical Medicine and Rehabilitation | Volume 14.
Issue 02, 2025 function, and QOL among KOA patients.
For instance.
Yildiz et al.
reported significant improvements in pain and function with ultrasound therapy in a randomized controlled trial11.
Similarly, systematic reviews have confirmed that TENS can enhance QOL beyond reductions in pain intensity, suggesting broader neuromodulatory and psychosocial effects7,10.
Indonesian populations, given that cultural differences may influence how patients perceive and report QOL18.
Long-term follow-up would also be valuable to determine whether the benefits observed here are sustained over time.
The lack of strong correlation between iQOL and ipain or iADL in our study suggests that QOL is influenced by multiple domains beyond physical symptoms.
Several plausible mechanisms may explain this finding.
First.
TENS is known to modulate pain through gate control theory and descending inhibitory pathways, which not only reduce pain perception but also influence central processing of discomfort and emotional well-being.
Second.
QOL domains capture psychosocial and emotional factors such as self-efficacy, confidence in mobility, and reduced anxiety, which are not directly measured by pain or ADL scores12.
Third.
USD may enhance tissue healing and joint circulation, contributing to a subjective sense of recovery even before measurable gains in daily function occur19.
Lastly, cultural and contextual factors may shape how patients perceive Auquality of life,Ay meaning that reductions in pain may not linearly translate to improved QOL if social participation or independence remain restricted20.
This study demonstrates that the Quality of Life (QOL) domain in the KOOS improved significantly but showed weak correlation with pain and activities of daily living (ADL), suggesting that QOL captures subjective dimensions beyond physical These findings support the conceptual expansion of KOOS over WOMAC, as KOOS integrates patient-perceived well-being and life satisfaction that are not represented in WOMAC.
Therefore.
KOOS provides a more comprehensive framework for evaluating knee osteoarthritis therapy Further studies with larger sample sizes and randomized controlled designs are warranted to strengthen these findings.
These findings underscore the importance of including QOL assessment in osteoarthritis outcome Evaluating therapy outcomes based only on pain or ADL risks overlooking relevant patientcentered aspects.
This implies that rehabilitation in Indonesia should integrate KOOS-QOL into clinical monitoring, beyond WOMAC alone, to provide a more holistic evaluation of patient progress.
This study has several limitations, including a small sample size .
and the absence of a control group, which limit the generalizability of the findings and reduce statistical power.
In addition, the intervention protocol was not standardized across participants, and only three KOOS domains .
ADL, and QOL) were analyzed, while the sport/recreation and symptoms domains were excluded6,7.
A strength of this study is the use of KOOS percentage scoring, which allowed comparability across domains and facilitated direct interpretation of severity levels.
Future studies should adopt randomized controlled trial (RCT) designs with larger and more diverse populations, ideally multi-center, and should also investigate cross-cultural validity of KOOS in CONCLUSION
REFERENCE