Quality of life measures have neglected to include a critical self-assessment component in pediatric sarcoma patients. Our report shows how children rate their own quality of life and how that varies over time after surgery. Using the Pediatric Outcomes Data Collection Instrument, quality of life data was prospectively collected and combined with a retrospective review of clinical parameters on 43 children with primary bone sarcoma, with an average followup of 3 years. Children reported good yet variable scores in five of the six domains. Lower scores were noted in the Sports/Physical Functioning domain, particularly in the first 12 months after surgery, with improvement seen up to 24 months after surgery. Tumor specific factors such as size larger than 8 cm and lower extremity location were negative predictors for Sports/Physical Functioning. The only demographic factor that predicted perceived quality of life scores was gender, with girls reporting lower scores in Sports/Physical Functioning, Pain/Comfort, and Global Functioning domains. The Pediatric Outcomes Data Collection Instrument gives discriminatory detailed textured evaluation of the outcome of children treated for skeletal sarcoma. Further development of quality of life measures is needed to allow its use in treatment selection.

Background The SF-36 is widely used to evaluate the health-related quality of life of patients with musculoskeletal tumors. The minimum clinically important difference (MCID) is useful for interpreting changes in functional scores because it defines the smallest change each patient may perceive. Since the MCID is influenced by the population characteristics, MCIDs of the SF-36 should be defined to reflect the specific conditions of orthopaedic oncology patients. Questions/purposes (1) What is the MCID of SF-36 physical component summary (PCS) and mental component summary (MCS) scores in patients with orthopaedic oncologic conditions when calculated with distribution-based methods? (2) What is the MCID of SF-36 PCS and MCS scores in patients with orthopaedic oncologic conditions when calculated by anchor-based methods? Methods Of all 960 patients who underwent surgery from 1999 to 2005, 32% (310) of patients who underwent musculoskeletal oncologic surgery and completed two surveys during postoperative follow-up were reviewed. We evaluated a dataset that ended in 2005, completing follow-up of data accrued as part of the cooperative effort between the American Academy of Orthopaedic Surgeons and the Council of Musculoskeletal Specialty Societies to create patient reported quality of life instruments for lower extremity conditions. This effort, started in 1994 was validated and widely accepted by its publication in 2004. We believe the findings from this period are still relevant today because (1) this critical information has never been available for clinicians and researchers to distinguish real differences in outcome among orthopaedic oncology patients, (2) the SF-36 continues to be the best validated and widely used instrument to assess health-related quality of life, and unfortunately (3) there has been no significant change in outcome for oncology patients over the intervening years. SF-36 PCS and MCS are aggregates of the eight scale scores specific to physical and mental dimension (scores range from 0 to 100, with higher scores representing better health). Their responsiveness has been shown postoperatively for several surgical procedures (such as, colorectal surgery). Two different methods were used to calculate the MCID: the distribution-based method, which was based on half the SD of the change in score and standard error of the measurement at baseline, and anchor-based, in which a receiver operating characteristic (ROC) curve analysis was performed. The anchor-based method uses a plain-language question to ask patients how their individual conditions changed when compared with the previous survey. Answer choices were “much better,” “somewhat better,” “about the same,” “somewhat worse,” or “much worse.” The ROC curve-derived MCIDs were defined as the change in scores from baseline, with sensitivity and specificity to detect differences in patients who stated their outcome was, about the same and those who stated their status was somewhat better or somewhat worse. This approach is based on each patient’s perception. It considers that the definition of MCID is the minimal difference each patient can perceive as meaningful. Results Using the distribution-based method, we found that the MCIDs of the PCS and MCS were 5 and 5 by half the SD, and 6 and 5 by standard error of the measurement. In the anchor-based method, the MCIDs of the PCS and MCS for improvement/deterioration were 4 (area under the curve, 0.82)/-2 (area under the curve, 0.79) and 4 (area under the curve, 0.72)/ (area under the curve, 0.68), respectively. Conclusions Since both anchor-based and distribution-based MCID estimates of the SF-36 in patients with musculoskeletal tumors were so similar, we have confidence in the estimates we made, which were about 5 points for both the PCS and the MCS subscales of the SF-36. This suggests that interventions improving SF-36 by less than that amount are unlikely to be perceived by patients as clinically important. Therefore, those interventions may not justify exposing patients to risk, cost, or inconvenience. When applying new interventions to orthopaedic oncology patients going forward, it will be important to consider these MCIDs for evaluation purposes. Level of Evidence Level III, diagnostic study.

The SF-36 is widely used to evaluate the health-related quality of life (HRQoL) of patients with musculoskeletal tumors. Instead of typical methods, calculating the SF-36 Global Score has recently become an increasingly common reporting approach. However, numerical changes lack clear clinical relevance. The minimal clinically important difference (MCID) is useful for interpreting changes in functional scores by defining the smallest change patients may perceive as clinically meaningful.The aim of this study is to determine the MCID of the SF-36 Global Score in orthopedic oncology patients, which has not been reported to date. Three-hundred ten patients who underwent surgery and completed two surveys during postoperative follow-up were reviewed. The two most common methods for calculating the SF-36 Global Score were used: (1) anchor-based methods and receiver operating characteristic analysis based on one-half of the SD of change score and standard error of measurement at baseline and; (2) distribution-based methods. Using anchor-based methods, the MCIDs of SF-36 Global Scores #1 and #2 were 2.7 (area under the curve [AUC] = 0.85) and 2.5 (AUC = 0.79) for improvement, and −1.5 (AUC = 0.81) and −0.6 (AUC = 0.83) for deterioration, respectively. Using distribution-based methods, the MCIDs of SF-36 Global Scores #1 and #2 were 4.1 and 4.4 by half SD, and 4.1 and 4.5 by standard error of measurement, respectively. Our findings provide benchmark values, which can serve as a reference for future studies in musculoskeletal tumor patients using the SF-36 Global Score as a single measure for HRQoL. K E Y W O R D S anchor-based method, distribution-based method, health-related quality of life (HRQoL), minimal clinically important difference (MCID), sarcoma, SF-36 Global Score 1 | BACKGROUND Patient-derived outcome assessments are essential determinants of health-related quality of life (HRQoL) in oncology and help inform treatment decisions for future musculoskeletal oncology patients. There has been a burgeoning of publications regarding HRQoL. 1 More generic instruments, such as SF-36 or Patient Reported Outcomes Measurement Information System, are validated internationally for general orthopedic conditions. 2,3 However, these have not been evaluated critically in musculoskeletal oncology, although