Validation of the Lymphedema Life Impact Scale Version 2: A Condition-Specific Measurement Tool for Persons With Lymphedema

Rasch validation and refinement of the Lymphedema Life Impact Scale version 2 in an Italian cohort with secondary lymphedema

PURPOSE

To produce and validate an Italian version of the Lymphedema Life Impact Scale version 2 (LLISv2-It), a tool measuring the impact of lymphedema on health-related quality of life, and investigate its main psychometric characteristics.

METHODS

After translation and cross-cultural adaptation of the LLISv2, we administered it to 156 subjects with secondary lymphedema (upper or lower limb), together with (depending on the limb involved) either the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) or the Lower Extremity Functional Scale (LEFS). We analyzed the performance of LLISv2-It using Classical Test Theory and Rasch methods.

RESULTS

Cronbach alpha was 0.89. Item fit statistics indicated that item #12 was underfitting (Infit MnSQ = 1.56; Outfit MnSq = 1.75). Test-retest reliability of the 17-item version (without item #18, not scored, according to the original authors) and of a 16-item version (without #12 and #18-a unidimensional item set) were both excellent (ICC2.1 = 0.93; 95%). The minimum detectable change was 8.9 points. The correlation of LLISv2-It with DASH and LEFS was r = 0.81 and -0.57, respectively.

CONCLUSIONS

The Italian version of the LLISv2 is reliable and valid. To make the tool more psychometrically sound, we recommend to not calculate items #12 and #18 in the total score.

IMPLICATIONS FOR REHABILITATIONThe Lymphedema Life Impact Scale (LLISv2) is particularly useful as a validated condition-specific health-related quality of life measure for patients with chronic edema/lymphedema. We have validated its Italian version (LLISv2-It).We also examined the psychometric properties of the LLISv2 in individuals with secondary lymphedema of either upper or lower limb, using both classical test theory and Rasch techniques, to provide insights for further refinement of the questionnaire.Based on our results, we recommend not to count item #12 in the total score (besides #18, as already suggested by the original authors). Moreover, we determined that the minimum detectable change of the LLISv2 was 9 points. This information is helpful in clinical practice to understand if the change in score is not due to chance (measurement error).Although further research is warranted, the present validation study of the LLISv2 increases the confidence in the metric quality and clinical utility of the scale to assess lymphedema-specific health-related quality of life in individuals with secondary lymphedema of either upper or lower limb.

Lower Quadrant Edema Patient-Reported Outcome Measure Is Reliable, Valid, and Efficient for Patients With Lymphatic and Venous Disorders

OBJECTIVE

The main aims of this study were: (1) to create a patient-reported outcome measure (PROM) item bank for measuring the impact of lower quadrant edema (LQE) on physical function using item response theory and (2) to assess reliability, validity, and administration efficiency of LQE PROM scores based on computerized adaptive test (CAT) and the reliability of a 10-item short form (SF).

METHODS

This retrospective study included data from patients treated in outpatient rehabilitation clinics for lower quadrant edema who responded to all 30 candidate items at intake. Item response theory model assumptions of unidimensionality, local item independence, item fit, and presence of differential item functioning (DIF) were evaluated. LQE-CAT-generated scores were assessed for reliability, validity, and administration efficiency. LQE-SF-generated scores were assessed for reliability.

RESULTS

The total cohort included 4894 patients (mean [SD] age = 65 [14] years; range = 14-89 years). A set of 20 items was selected for the item bank based on support for its unidimensionality and fit to the item response theory model, with reliability estimates greater than 0.92 for CAT and SF administration modes. No items demonstrated DIF with respect to tested variables. After controlling for scores at intake, scores discriminated among multiple patient groups in clinically logical ways with better outcomes observed for patients who were younger with less chronic symptoms and fewer comorbidities. Scores were responsive to change but the effect size was small (0.4). There were negligible floor and ceiling effects. CAT administration of the item bank required an average of 6.1 items (median = 5). Scores correlated highly with full-bank scores (Pearson correlation coefficient = 0.98).

CONCLUSION

Scores on the LQE PROM were reliable, valid, and efficient for assessing perceived physical function of patients with lower quadrant edema. The LQE, CAT, and SF are suitable for research and routine clinical care. Reasons for the small effect size for change scores should be studied.

IMPACT

The newly developed LQE PROM was reliable and valid and offered efficient administration modes for assessing perceived physical function of patients with LQE, both for research and routine clinical care in busy outpatient rehabilitation settings. As an item response theory-based measure, the LQE PROM allows administration of condition-specific functional questions with low response burden for patients. The 10-item LQE-SF offers a feasible alternative administration mode when CAT administration is not available. This study supports a transition to PROMs that are based on modern measurement approaches to achieve the combined benefits of high accuracy and efficiency.

Community-based outpatient cancer rehabilitation services for women with gynecologic cancer: acceptability and impact on patient-reported outcomes

OBJECTIVE

Women with gynecologic cancers often experience functional impairments impacting quality of life. Physical and occupational therapy (PT/OT) treat functional impairment; however, the acceptability and impact of these services for women with gynecologic cancer are unknown.

METHODS

We reviewed rehabilitation charts of women with gynecologic cancer who received PT/OT (i.e., patients) in 2019 and completed patient-reported outcome measures (PROMs) selected by their therapist at intake (pre) and discharge (post). We calculated descriptive statistics for patient, rehabilitation, and acceptability (0-10) data. For PROM data, we used paired samples t-tests to evaluate pre-post change, and then calculated effect size (Hedge's g) and the proportion who achieved a minimal detectable change (MDC).

RESULTS

PT/OT patients (N = 84) were 64.63 ± 11.04 years old with predominant diagnoses of ovarian (41.7%) or endometrial (32.1%) cancer. They attended a median of 13 sessions (IQR = 8.0-19.0). Sessions were predominantly PT (86%) vs. OT (14%). Median acceptability was 10 (IQR = 9.8-10.0). Pre-post improvement was observed for each of the 17 PROMs used by therapists. Significant improvement (p < .05) was observed for four PROMs: the Patient-Specific Functional Scale (M∆ = 2.93 ± 2.31, g = 1.47, 71% achieved MDC), the Lower Extremity Functional Scale (M∆ = 12.88 ± 12.31, g = 0.61, 60% achieved MDC), the Lymphedema Life Impact Scale (M∆ = 20.50 ± 20.61, g = 1.18, 58% achieved MDC), and the Modified Fatigue Impact Scale (M∆ = 6.55 ± 9.69, g = 0.33, 7% achieved MDC).

CONCLUSION

PT/OT was acceptable and improved patient-reported outcomes for women with gynecologic cancers. Future research is needed to establish gynecologic-specific guidelines for referral and PT/OT practice.

Accuracy, Sensitivity, and Specificity of the LLIS and ULL27 in Detecting Breast Cancer-Related Lymphedema

INTRODUCTION

Breast cancer-related lymphedema occurs in up to 30% of women following axillary lymph node dissection (ALND) and less commonly following sentinel lymph node biopsy. To quantify disability in these patients, patient-reported outcome measures (PROMs) have proven useful; however, given the overlap of symptoms between ALND and lymphedema, examination of their accuracy, sensitivity, and specificity in detecting lymphedema in breast cancer patients undergoing ALND is needed.

METHODS

The Lymphedema Life Impact Scale (LLIS) and the Upper Limb Lymphedema 27 scale (ULL27) were administered to patients who had undergone ALND at least 2 years prior and either did or did not develop lymphedema. Survey responses and the degree of disability were compared to generate receiver operator characteristic (ROC) curves, and the sensitivity and specificity of PROMs to diagnose lymphedema were analyzed.

RESULTS

Both PROMs were highly accurate, sensitive, and specific for detecting lymphedema. The LLIS had an accuracy of 97%, sensitivity of 100%, and specificity of 84.8% at a cutoff of ≥ 5.88 overall percent impairment score (higher scores indicate worse disability). The ULL27 had an accuracy of 93%, sensitivity of 88.6%, and specificity of 90.9% at a cutoff of ≤ 83.3 global score (lower scores indicate worse disability).

CONCLUSIONS

The LLIS and the ULL27 appear to be highly specific for lymphedema and capable of differentiating it from symptoms resulting from ALND alone. Our findings suggest that use of these questionnaires with a threshold may be effective for diagnosing lymphedema, potentially reducing the need for frequent clinic visits and time-consuming measurements.

Upper Quadrant Edema Patient-Reported Outcome Measure Is Reliable, Valid, and Efficient for Patients With Lymphatic and Venous Disorders

OBJECTIVE

The main aims of this study were to (1) create a patient-reported outcome measure (PROM) item bank for measuring the impact of upper quadrant edema (UQE) on physical function by calibrating responses to newly developed items; and (2) assess reliability, validity, and administration efficiency of scores based on computerized adaptive test (CAT) and 10-item short-form (SF) administration modes.

METHODS

This was a retrospective study including data from patients treated in outpatient rehabilitation clinics for UQE that responded to all 27 candidate items at intake. Item response theory model assumptions of unidimensionality, local item independence, item fit, and presence of differential item functioning were evaluated. UQE-CAT- and UQE-SF-generated scores were assessed for reliability, validity, and administration efficiency.

RESULTS

The total cohort included 3486 patients (mean [SD] age = 61 [13] years; range = 14-89 years). After removing 2 items, a 25-item solution was supported for its unidimensionality and fit to the item response theory model with reliability estimates of more than 0.93 for scores based on both CAT and SF administration modes. No items demonstrated differential item functioning. Scores discriminated among multiple patient groups in clinically logical ways and were moderately responsive to change with negligible floor and acceptable ceiling effects. CAT scores were generated using an average of 5.6 items (median = 5).

CONCLUSION

Scores on the UQE PROM were reliable, valid, and efficient for assessing perceived physical function of patients with upper quadrant edema; thus, the measure is suitable for research and routine clinical administration.

IMPACT

The newly developed UQE PROM is reliable and valid and offers efficient administration modes for assessing perceived physical function of patients with UQE caused by lymphatic and venous disorders, both for research and routine clinical care in busy outpatient rehabilitation settings. As an item response theory-based measure, the UQE PROM allows administration of condition-specific functional questions with low response burden for patients. This study supports a transition to PROMs that are based on modern measurement approaches to achieve high accuracy and efficiency.

Measurement Properties of the Lymphedema Life Impact Scale

Background: The updated Lymphedema Life Impact Scale (LLIS, version 2) has been widely used to evaluate the effect of lymphedema from the patient's perspective. We sought to assess its ability to accurately and efficiently measure lymphedema-related impact using modern psychometric techniques. Methods and Results: We collected a total of 1054 patient-reported outcome measure scores from 285 patients with upper extremity lymphedema and 65 patients with lower extremity lymphedema between 2016 and 2020. We first evaluated the relationship between the LLIS score, L-Dex score, and limb volume difference (LVD), and used classical test and item response theories to assess its psychometric performance. The LLIS score was only very weakly associated with LVD (r = 0.17, p < 0.001) and L-Dex score (r = 0.22, p < 0.001). The LLIS had acceptable dimensionality. Items 7 (affects body image) and 16 (affects proper fit of clothing/shoes) were locally dependent (Yen's Q3 = 0.45). Eight of the 17 items was interpreted differently between upper and lower limb lymphedema patients (pseudo R² ≥ 0.01). The scoring structure required correction for items 9 (affects intimate relations) and 12 (manages lymphedema). Removing items 18 (infection occurrence) and 7 resulted in substantially improved item response theory model fit (Tucker-Lewis index = 0.93, comparative fix index = 0.95, root mean square error of approximation = 0.07, and root means square of the residual = 0.06). The relationships between the LLIS and objective measures of lymphedema remained weak following modification (LVD; r = 0.13, p = 0.01, L-Dex; r = 0.26, p < 0.001). Conclusion: We were able to slightly improve the psychometric properties of the LLIS. However, these improvements did not rectify apparent issues with construct validity and both versions of the LLIS displayed a weak relationship with objective measures of lymphedema severity.

Development of the Lymphoedema Patient Reported Outcome Measure (LYMPROM)

To ensure lymphoedema patients in Wales receive the right care, at the right time, by the right person, patient-reported outcome measures (PROMs) were routinely completed within the All-Wales lymphoedema assessment documentation. This evaluation describes the development of the Lymphoedema Patient Reported Outcome Measure (LYMPROM), which is a tool developed by Lymphoedema Network Wales clinicians and key stakeholders. The tool was explored for face, form and content validity during 3 months in 2019; 128 anonymised completions of LYMPROM were reviewed to establish feasibility, acceptability and internal validity using Cronbach's alpha. LYMPROM was feasible and acceptability was high. Face and content validity were reported (i-CVI [item content validity index] range=0.43 - 1; s-CVI/Ave=0.94) and internal consistency was excellent (0.958). LYMPROM was easily integrated within lymphoedema services in Wales, promoting patient-led care and supporting value-based health care. Further evaluations of reliability and validity of LYMPROM are proceeding along with digital integration.

The Reliability and Validity of the Turkish Version of the Lymphedema Life Impact Scale in Patients With Breast Cancer-Related Lymphedema

BACKGROUND

Health-related quality of life is measured to detect the influence of lymphedema on physical, functional, and social aspects of life in patients with breast cancer-related lymphedema (BCRL).

OBJECTIVE

This study aimed to perform the psychometric evaluation of the Lymphedema Life Impact Scale (LLIS) in Turkish patients with BCRL.

METHODS

Patients with BCRL (n = 78) filled out the Turkish LLIS, Lymphedema Quality of Life, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, and Quick Disability of Arm, Shoulder and Hand scales. Breast cancer survivors without BCRL (n = 35) completed only the Turkish LLIS. Psychometric properties were analyzed with the internal consistency, test-rest reliability, construct, criterion, and discriminant validity.

RESULTS

The internal consistency of the Turkish LLIS was strong (Cronbach's α coefficient >.70). Test-retest reliability was strong to very strong (intraclass correlation coefficients from 0.88 to 0.93; P < .001). Similar to the original structure of the scale, exploratory factor analysis identified 3 factors. Criterion validity was supported by moderate to strong correlations between the LLIS, Lymphedema Quality of Life, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, and quick Disability of Arm, Shoulder and Hand. There were significant differences in the total and subscale scores of the LLIS between participants with and without BCRL (P < .05).

CONCLUSIONS

The present study provided the evidence to confirm reliability and clinical validity of the Turkish LLIS.

IMPLICATIONS OF PRACTICE

The Turkish LLIS is a reliable and valid condition-specific scale to measure the physical, functional, and psychological aspects of health-related quality of life in patients with BCRL.

Patient-Reported Outcome Measures in Lymphedema: A Systematic Review and COSMIN Analysis

BACKGROUND

Lymphedema is a chronic and debilitating condition that affects many cancer survivors. Patient-reported outcome measures (PROMs) can give valuable insight into the impact of lymphedema on a patient's quality of life and can play an essential role in treatment decisions. This study aims to (1) identify PROMs used to assess health-related quality of life (HRQoL) in patients with lymphedema; and (2) assess the quality of the lymphedema-specific PROMs.

METHODS

We performed a systematic search to identify articles on lymphedema, quality of life, and PROMs. An overview was created of all PROMs used to assess HRQoL in patients with lymphedema. The methodological quality of the lymphedema-specific PROMs was assessed using the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) criteria.

RESULTS

A total of 235 articles met the inclusion criteria, of which 200 described studies using one or more PROMs as an outcome measure in patients with lymphedema. The other 35 studies described the development and/or validation of a lymphedema-specific PROM. The COSMIN assessment demonstrated that none of these PROMs met all quality standards for development.

CONCLUSION

The use of PROMs in lymphedema is increasing; however, based on our findings, we cannot fully support the use of any of the existing instruments. A well-developed lymphedema-specific PROM, based on patient input, is needed to gain better insight into the impact of this condition, and can be used to measure the effect of possible medical and surgical treatments.

Self-reported questionnaires for lymphoedema: a systematic review of measurement properties using COSMIN framework

INTRODUCTION

Lymphoedema may develop as a result of numerous genetic and traumatic causes; however, treatment for cancer is the most common cause of its development in more economically developed nations. This systematic review critically appraised, compared and summarised the measurement properties of lymphoedema-specific self-reported questionnaires (SRQs) measuring various patient-reported outcomes including quality of life (QOL), function, morbidity, and symptoms.

METHODS

Seven databases were searched to identify studies of the measurement properties of SRQs. Two review teams independently evaluated the quality of the individual studies using the risk of bias tool from the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN). Measurement properties of the SRQs presented in the studies were then rated. Study level ratings were summarised for an SRQ if they were reported in multiple studies, and their overall quality of the evidence were then graded.

RESULTS

Forty articles, reporting on 19 SRQs were identified from 8615 records. The focus of the 19 SRQs included eight on QOL, four on symptoms, two on function, and two on impairment. The other three SRQs were on illness perception, self-efficacy, and patient-relevant treatment benefit, respectively. Eight and three SRQs were upper limb and lower limb-specific, respectively, whereas seven questionnaires were for both upper and lower limb lymphoedema. One SRQ was developed for head and neck lymphoedema. According to the COSMIN framework, none of the SRQs reviewed had sufficient evidence to support all nine measurement properties. In lower limb questionnaires, the LYMQOL-leg has sufficient content, structural, and construct validity as well as internal consistency and reliability. For upper limb lymphoedema questionnaires, the Lymph-ICF-UL had sufficient content and construct validity as well as reliability.

CONCLUSION

LYMQOL-leg SRQ is recommended with confidence for evaluation of QOL of people with lower limb lymphoedema while the Lymph-ICF-UL is recommended for evaluation of the QOL of the breast cancer-related lymphoedema with some confidence. In view of the high level of the indeterminate ratings of the measurement properties of the existing SRQs, further research is desirable.

Patient-reported outcomes following lymph reconstructive surgery in lower limb lymphedema: A systematic review of literature

OBJECTIVE

Lymphedema is a chronic, progressive and burdensome disease that is known to have a substantial impact on quality of life (QOL). Hence, the assessment of QOL is an important aspect of any study which seeks to evaluate outcomes after lymph reconstructive surgery. We therefore aimed to analyze currently available patient-reported outcome measurements (PROMS) for patients with lower limb lymphedema (LLL) with regard to their psychometric properties. Furthermore, we intended to evaluate the change in QOL in patient undergoing lymphovenous anastomosis (LVA) or vascularized lymph node transfer (VLNT).

METHODS

A literature research of four databases on studies that included PROMS for LLL was conducted. All selected studies were assessed for validity according Consensus-based Standards for the selection of Health Measurement Instruments. Studies that used the Lymph Quality of Life Measure for Limb Lymphedema (LYMQOL) after LVA and/or VLNT were included for quantitative analysis.

RESULTS

In total, 988 studies were screened, of which 30 studies were included in this review. We identified six validated PROMS to assess LLL. Of those, the LYMQOL was the most commonly used questionnaire. Based on the LYMQOL, a significant improvement of QOL in LLL was noted in all studies after reconstructive lymph surgery (LVA/VLNT) regardless of lymphedema etiology, stage, or time since diagnosis. On the basis of the Consensus-based Standards for the selection of Health Measurement Instruments criteria, the Lymphoedema Functioning, Disability and Health Questionnaire for Lower Limb Lymphoedema seems to be superior in terms of its psychometric properties.

CONCLUSIONS

A significant improvement in the QOL in patients with LLL after reconstructive lymph surgery can be observed. Future studies on reconstructive lymph surgery need to include both objective and congruent volume measurements, as well as data on QOL based a well-validated PROM such as the Lymphoedema Functioning, Disability and Health Questionnaire for Lower Limb Lymphoedema.