Minimal important change and patient acceptable symptom state for patients after proximal interphalangeal joint arthroplasty

Proximal interphalangeal joint arthroplasty: current trends and evidence-based practice

Arthroplasty of the proximal interphalangeal joint (PIPJ) has evolved since its inception over 60 years ago. This review examines the indications for surgery, highlights the differences in current arthroplasty designs, variances in surgical techniques, clinical controversies, current implant outcomes data and salvage options for the failed implant. Overall, PIPJ implant arthroplasty is a good and reliable option for symptomatic PIPJ degenerative, post-traumatic or inflammatory arthritis given the proper clinical setting. If current techniques for implantation and rehabilitation are followed, predictable pain relief and satisfactory function can be anticipated. The purpose of this review article is to examine the current evidence-based indications for PIPJ arthroplasty and examine the reported, implant-specific outcomes of this procedure. Various techniques and rehabilitation strategies will also be outlined.

Patient-Rated Wrist Evaluation Threshold for Successful Open Surgery of the Triangular Fibrocartilage Complex

Purpose  To determine thresholds in patient-reported outcome measures at baseline in patients electing to undergo triangular fibrocartilage complex (TFCC) surgery to select patients with clinically improved outcomes. Methods  The study cohort comprised consecutive patients who underwent open TFCC repair between December 2011 and December 2018 in various clinics in the Netherlands. All patients were asked to complete the patient-rated wrist evaluation (PRWE) questionnaire at baseline as well as at 12 months postoperatively. The minimal clinically important difference (MCID) for the PRWE was calculated to be 24 using an anchor-based method. We compared patient, disease, and surgical characteristics between patients who did and did not reach the MCID. The t -tests and chi-square tests were undertaken to test differences between outcomes and satisfaction in patients who did or did not reach the MCID. Results  Patients (34%) who did not reach MCID had a longer history of complaints. The chances of reaching the MCID for patients with a low PRWE score at baseline were slim. Of patients with a PRWE score <34 at baseline, only 14% reached the MCID, whereas in patients with a PRWE score of ≥34, 69% reached the MCID. Conclusion  A PRWE total score at baseline <34 is a strong signal to reconsider open surgery of the TFCC because the chance of reaching a clinically meaningful outcome is slim. Level of Evidence  II. Type of Study  Therapeutic.

Prosthetic arthroplasty of the proximal interphalangeal joint using a surface replacing implant (CapFlex-PIP): 3-year outcomes

Level of evidence: IV.

Preoperative Thresholds of Pain and Function to Achieve a Minimal Important Change and Patient Acceptable Symptom State After Proximal Interphalangeal Joint Arthroplasty

PURPOSE

There is ongoing discussion about the level of symptoms patients with proximal interphalangeal (PIP) joint osteoarthritis should have to undergo surgery. The aims of our study were to determine the minimal important change (MIC) and patient acceptable symptom state (PASS) for PIP joint range of motion (ROM), and define clinically relevant thresholds of preoperative pain and function at which patients have the greatest chance to achieve a MIC and PASS in these outcomes 1 year after PIP arthroplasty.

METHODS

We analyzed registry data that included patients with PIP joint osteoarthritis who underwent an arthroplasty for this condition and had a 1-year follow-up. Patients indicated pain on a numeric rating scale (0-10) and completed the brief Michigan Hand Outcomes Questionnaire (MHQ). Active total PIP ROM was measured. The preoperative thresholds, predictive of achieving the MIC and PASS for each outcome measure of pain, function, and ROM, were determined using receiver operating characteristics curves.

RESULTS

We included 196 patients who experienced a relevant improvement in ROM (= MIC) when there was an increase by ≥8° compared with the ROM preoperatively. Patients were satisfied with their postoperative ROM (= PASS) if they achieved PIP mobility of at least 66°. Pain at rest and during activities was predictive for achieving a MIC but not a PASS. Due to an insufficient area under the curve for the brief MHQ and ROM, their baseline values cannot predict the postoperative achievement of MIC or PASS. We suggest that patients with preoperative pain at rest ≥4.5 or pain during activities ≥5.5 have the greatest chance of achieving a subjectively relevant change 1 year after surgery.

CONCLUSIONS

The determined thresholds may support surgeons in the preoperative process of deciding for or against a surgical intervention and explain the probability of achieving sufficient postoperative symptom relief for the patient.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.

Establishing the Patient Acceptable Symptom State in a Nonshoulder Hand and Upper Extremity Population for the QuickDASH and PROMIS UE Computer Adaptive Tests

PURPOSE

It is unclear what score thresholds on patient-reported outcomes instruments reflect an acceptable level of upper extremity (UE) function from the perspective of patients undergoing hand surgery. The purpose of this study was to calculate the patient acceptable symptom state (PASS) for the Disabilities of the Arm, Shoulder, and Hand (QuickDASH) and Patient-Reported Outcomes Measurement Information System (PROMIS) UE Computer Adaptive Test (CAT), version 2.0, in a population who underwent hand surgery.

METHODS

Adult patients who underwent hand surgery between February 2019 and December 2019 at a single academic tertiary institution were identified. QuickDASH and PROMIS UE CAT version 2.0 scores were collected 1 year after surgery, as were separate symptom- and function-specific anchor questions that queried the acceptability of patients' current state. Threshold values predictive of a patient reporting an acceptable symptom state (PASS[+]) were calculated for both instruments using the 75th percentile score for patients in the PASS(+) group and the Youden Index as determined by receiver operating curve (ROC) analysis.

RESULTS

A total of 222 patients were included. QuickDASH and PROMIS UE CAT scores differed significantly between the PASS(+) and PASS(-) groups. The 75th percentile method yielded PASS values of <16 for the QuickDASH and >43 for the PROMIS UE CAT for both anchor questions. The ROC analysis yielded PASS estimates of <15.9 to <20.5 for the QuickDASH and >38.1 to >46.2 for the PROMIS UE CAT, with ranges calculated from differing threshold values for each of the 2 anchor questions. The ROC-based estimates demonstrated high levels of model discrimination (area under the curve ≥ 0.80).

CONCLUSIONS

We propose PASS estimates obtained using the 75th percentile and ROC methods.

CLINICAL RELEVANCE

Specifically, PASS values in the range of 15.9-20.5 for the QuickDASH and 38.1-46.2 for the PROMIS UE CAT version 2.0 should be used when interpreting outcomes at a population level.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

Symptom and Treatment Satisfaction in Members of the US and Canadian GBS/CIDP Foundations with a Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy

INTRODUCTION

Current guidelines for defining good outcomes in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) are predominately defined by experts. At present, we do not have a patient-anchored definition of what constitutes a "good" outcome. Our study aimed to assess the symptom burden of people living with CIDP, as well as satisfaction with treatments and clinical outcomes.

METHODS

We conducted an online-survey in CIDP patients registered with the US and Canadian GBS/CIDP foundations. Respondents answered general demographic and clinical questions, as well as satisfaction with current symptom burden and treatments, plus validated outcome measures.

RESULTS

A total of 318 individuals with self-reported CIDP completed the online survey, of whom 128 (40%) considered their current disease burden as satisfactory while 190 (60%) did not. Of 305 patients who answered the treatment satisfaction question, 222(74%) were satisfied with their treatments. Patients who were satisfied with their current symptoms had, on average, better scores in quality of life and disease severity scales, although regression modeling showed that only ability to walk, stable symptoms, and health utility scores were associated with symptom satisfaction. Treatment satisfaction was associated with stable symptoms, use of IVIG, and use of one versus no medication.

CONCLUSIONS

A high proportion of members of the US and Canadian GBS/CIDP Foundations reporting a diagnosis of CIDP were unsatisfied with current symptoms, despite a high level of overall satisfaction with treatments. There is an unmet need for improving long-term outcomes in people with a diagnosis of CIDP, and for studying patient-centered long-term treatment goals.

Does distal interphalangeal joint arthrodesis affect proximal interphalangeal joint arthroplasty outcomes in the same finger?

The purpose of this study was to analyse the 1-year outcomes after combining a surface replacing proximal interphalangeal joint arthroplasty and a distal interphalangeal screw arthrodesis and to compare the combined surgery with proximal interphalangeal joint arthroplasty alone. To obtain two groups with similar baseline data from our prospective registry, propensity score matching was used to match 23 fingers with the combined operations with 115 fingers with proximal interphalangeal joint arthroplasty alone. One year after surgery, the mean ranges of motion were 60° (95% CI: 53° to 67°) in the combined group and 63° (95% CI: 60° to 66°) in the control group and did not differ significantly. Grip strength, the brief Michigan Hand Questionnaire and pain also did not differ between the groups 1 year after surgery. All the proximal interphalangeal implants in patients treated with a distal interphalangeal screw arthrodesis remained in situ. Combining proximal interphalangeal joint arthroplasty with distal interphalangeal arthrodesis leads to 1-year outcomes that are similar to those achieved by proximal interphalangeal joint replacement alone.Level of evidence: III.

Reported Outcomes and Outcome Measures in Proximal Interphalangeal Joint Arthroplasty: A Systematic Review

Purpose: There is a lack of scientific consensus on the best arthroplasty implant option for proximal interphalangeal joint (PIPJ) arthritis, due to diversity in outcome reporting and measurement methods. The development of a standardized core outcome set (COS) and standard outcome measures could mitigate this issue. This study catalogs the reported outcomes and outcome measures found in PIPJ arthroplasty studies, which can be used in the first step of developing a COS. Methods: A database search of MEDLINE, EMBASE, and Web of Science (January 1, 2010, to March 10, 2021) was performed to retrieve studies that reported outcomes of the 3 most common primary PIPJ arthroplasty implants: silicone, pyrocarbon, and metal-polyethylene. The primary objectives of this study include reported outcomes and outcome measures. Secondary objectives include clinimetric properties of outcome measures, study design, and implant types. Results: Fifty articles met inclusion criteria. Of the included studies, 41 (82%) were case series, 8 (16%) were cohort studies, and 1 (2%) was a randomized control trial. Thirty-three unique outcomes were identified. Fifteen (46%) outcomes were clinician-reported and 26 (79%) were patient-reported. Eighteen unique outcome measures were identified. Of the outcome measures, 15 (83%) were patient-reported, 1 (6%) was clinician-reported, and 2 (11%) were reported by both patients and clinicians. Conclusions: Substantial heterogeneity was found in reported outcomes and outcome measures across studies evaluating PIPJ arthroplasty, impeding knowledge translation. The development of a COS for PIPJ arthroplasty is necessary to help compare and pool data across studies, and advance scientific knowledge.

What Are the Minimally Important Changes of Four Commonly Used Patient-reported Outcome Measures for 36 Hand and Wrist Condition-Treatment Combinations?

BACKGROUND

Patient-reported outcome measures (PROMs) are frequently used to assess treatment outcomes for hand and wrist conditions. To adequately interpret these outcomes, it is important to determine whether a statistically significant change is also clinically relevant. For this purpose, the minimally important change (MIC) was developed, representing the minimal within-person change in outcome that patients perceive as a beneficial treatment effect. Prior studies demonstrated substantial differences in MICs between condition-treatment combinations, suggesting that MICs are context-specific and cannot be reliably generalized. Hence, a study providing MICs for a wide diversity of condition-treatment combinations for hand and wrist conditions will contribute to more accurate treatment evaluations.

QUESTIONS/PURPOSES

(1) What are the MICs of the most frequently used PROMs for common condition-treatment combinations of hand and wrist conditions? (2) Do MICs vary based on the invasiveness of the treatment (nonsurgical treatment or surgical treatment)?

METHODS

This study is based on data from a longitudinally maintained database of patients with hand and wrist conditions treated in one of 26 outpatient clinics in the Netherlands between November 2013 and November 2020. Patients were invited to complete several validated PROMs before treatment and at final follow-up. All patients were invited to complete the VAS for pain and hand function. Depending on the condition, patients were also invited to complete the Michigan Hand outcomes Questionnaire (MHQ) (finger and thumb conditions), the Patient-rated Wrist/Hand Evaluation (PRWHE) (wrist conditions), or the Boston Carpal Tunnel Questionnaire (BCTQ) (nerve conditions). Additionally, patients completed the validated Satisfaction with Treatment Result Questionnaire at final follow-up. Final follow-up timepoints were 3 months for nonsurgical and minor surgical treatment (including trigger finger release) and 12 months for major surgical treatment (such as trapeziectomy). Our database included 55,651 patients, of whom we excluded 1528 who only required diagnostic management, 25,099 patients who did not complete the Satisfaction with Treatment Result Questionnaire, 3509 patients with missing data in the PROM of interest at baseline or follow-up, and 1766 patients who were part of condition-treatment combinations with less than 100 patients. The final sample represented 43% (23,749) of all patients and consisted of 36 condition-treatment combinations. In this final sample, 26% (6179) of patients were managed nonsurgically and 74% (17,570) were managed surgically. Patients had a mean ± SD age of 55 ± 14 years, and 66% (15,593) of patients were women. To estimate the MIC, we used two anchor-based methods (the anchor mean change and the MIC predict method), which were triangulated afterward to obtain a single MIC. Applying this method, we calculated the MIC for 36 condition-treatment combinations, comprising 22 different conditions, and calculated the MIC for combined nonsurgical and surgical treatment groups. To examine whether the MIC differs between nonsurgical and surgical treatments, we performed a Wilcoxon signed rank test to compare the MICs of all PROM scores between nonsurgical and surgical treatment.

RESULTS

We found a large variation in triangulated MICs between the condition-treatment combinations. For example, for nonsurgical treatment of hand OA, the MICs of VAS pain during load clustered around 10 (interquartile range 8 to 11), for wrist osteotomy/carpectomy it was around 25 (IQR 24 to 27), and for nerve decompression it was 21. Additionally, the MICs of the MHQ total score ranged from 4 (nonsurgical treatment of CMC1 OA) to 15 (trapeziectomy with LRTI and bone tunnel), for the PRWHE total score it ranged from 2 (nonsurgical treatment of STT OA) to 29 (release of first extensor compartment), and for the BCTQ Symptom Severity Scale it ranged from 0.44 (nonsurgical treatment of carpal tunnel syndrome) to 0.87 (carpal tunnel release). An overview of all MIC values is available in a freely available online application at: https://analyse.equipezorgbedrijven.nl/shiny/mic-per-treatment/. In the combined treatment groups, the triangulated MIC values were lower for nonsurgical treatment than for surgical treatment (p < 0.001). The MICs for nonsurgical treatment can be approximated to be one-ninth (IQR 0.08 to 0.13) of the scale (approximately 11 on a 100-point instrument), and surgical treatment had MICs that were approximately one-fifth (IQR 0.14 to 0.24) of the scale (approximately 19 on a 100-point instrument).

CONCLUSION

MICs vary between condition-treatment combinations and differ depending on the invasiveness of the intervention. Patients receiving a more invasive treatment have higher treatment expectations, may experience more discomfort from their treatment, or may feel that the investment of undergoing a more invasive treatment should yield greater improvement, leading to a different perception of what constitutes a beneficial treatment effect.

CLINICAL RELEVANCE

Our findings indicate that the MIC is context-specific and may be misleading if applied inappropriately. Implementation of these condition-specific and treatment-specific MICs in clinical research allows for a better study design and to achieve more accurate treatment evaluations. Consequently, this could aid clinicians in better informing patients about the expected treatment results and facilitate shared decision-making in clinical practice. Future studies may focus on adaptive techniques to achieve individualized MICs, which may ultimately aid clinicians in selecting the optimal treatment for individual patients.

Minimal important difference and patient acceptable symptom state for the Numerical Rating Scale (NRS) for pain and the Patient-Rated Wrist/Hand Evaluation (PRWHE) for patients with osteoarthritis at the base of thumb

Background

The Numerical Rating Scale (NRS) and Patient-rated wrist/hand evaluation (PRWHE) are patient-reported outcomes frequently used for evaluating pain and function of the wrist and hand. The aim of this study was to determine thresholds for minimal important difference (MID) and patient acceptable symptom state (PASS) for NRS pain and PRWHE instruments in patients with base of thumb osteoarthritis.

Methods

Fifty-two patients with symptomatic base of thumb osteoarthritis wore a splint for six weeks before undergoing trapeziectomy. NRS pain (0 to 10) and PRWHE (0 to 100) were collected at the time of recruitment (baseline), after splint immobilization prior to surgery, and at 3, 6, 9 and 12 months after surgery. Four anchor-based methods were used to determine MID for NRS pain and PRWHE: the receiver operating characteristics (ROC) curve, the mean difference of change (MDC), the mean change (MC) and the predictive modelling methods. Two approaches were used to determine PASS for NRS pain and PRWHE: the 75^th percentile and the ROC curve methods. The anchor question for MID was the change perceived by the patient compared with baseline; the anchor question for PASS was whether the patient would be satisfied if the condition were to stay similar. The correlation between the transition anchor at baseline and the outcome at all time points combined was calculated using the Spearman’s rho analysis.

Results

The MID for NRS pain was 2.5 using the ROC curve method, 2.0 using the MDC method, 2.8 using the MC method, and 2.5 using the predictive modelling method. The corresponding MIDs for PRWHE were 22, 24, 10, and 20. The PASS values for NRS pain and PRWHE were 2.5 and 30 using the ROC curve method, and 2.0 and 22 using the 75th percentile method, respectively. The area under curve (AUC) analyses showed excellent discrimination for all measures.

Conclusion

We found credible MID estimates for NRS and PRWHE (including its subscales), although the MID estimates varied depending on the method used. The estimates were 20-30% of the range of scores of the instruments. The cut-offs for MID and PASS showed good or excellent discrimination, lending support for their use in future studies.

Trial registration

This clinimetrics study was approved by the Helsinki University ethical review board (HUS1525/2017).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01600-1.

Minimal clinically important difference, substantial clinical benefit, and patient acceptable symptom state of PROMIS upper extremity after total shoulder arthroplasty

Background

The Patient-Reported Outcomes Measurement Information System minimal clinically important difference (PROMIS MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) of patient-reported outcome measures provide clinical significance to patient-reported outcome measures scores. The goal of this study is to measure the MCID, SCB, and PASS of PROMIS Upper Extremity v2.0 (PROMIS UE) in patients undergoing total shoulder arthroplasty (TSA).

Methods

All patients who underwent TSA since October 2017 were identified from our institutional database. Patients who had completed the PROMIS UE outcome measure before surgery were asked to complete a PROMIS UE and anchor survey that contained two transition questions to assess patient satisfaction and change in symptoms since treatment. The anchor-based MCID, SCB, and PASS were calculated as the change in PROMIS UE score that represented the optimal cutoff for a receiver operating characteristic curve. The distribution-based MCID was calculated as a range between the average standard error of measurement multiplied by 2 different constants: 1 and 2.77.

Results

This study enrolled 165 patients. The anchor-based MCID for PROMIS UE was calculated to be 8.05 with an AUC of 0.814. The anchor-based SCB was calculated to be 10.0 with an AUC of 0.727. The distribution-based MCID was calculated to be between 3.12 and 8.65. The PASS was calculated to be 37.2 with an AUC of 0.90.

Conclusions

The establishment of MCID, SCB, and PASS for PROMIS UE scores after shoulder arthroplasty provides meaningful and objective clinical interpretation of the improvements in outcome scores after TSA.

Surface replacing arthroplasty of the proximal interphalangeal joint using the CapFlex-PIP implant: a prospective study with 5-year outcomes

The purpose of this prospective study was to evaluate the 5-year outcomes in patients after proximal interphalangeal joint arthroplasty using the surface replacing implant, CapFlex-PIP. Ninety-two prosthesis were implanted and 65 patients with 68 implants were available for follow-up. The brief Michigan Hand Outcomes Questionnaire score improved significantly from 45 (SD 15) before surgery to 71 (SD 17) at 5 years. On the numeric rating scale, pain during activities decreased significantly from 6.4 (SD 1.9) to 1.8 (SD 1.9). Range of motion of the joints increased significantly from 45° (SD 21) to 54° (SD 24). An axis deviation of more than 5° was found in 65% of the joints before surgery, but only in 25% at 5 years. Soft tissue reoperations were performed on eight patients. Four out of 92 implants underwent revision for stiffness or implant loosening. In three implants, the distal component migrated without needing revision. Overall, the CapFlex-PIP implant demonstrates favourable medium-term results in surface replacing arthroplasty of the proximal interphalangeal joint.Level of evidence: IV.

Validity, responsiveness and minimal important change of the EQ-5D-5L in patients after rotator cuff repair, shoulder arthroplasty or thumb carpometacarpal arthroplasty

PURPOSE

The aim was to investigate the measurement properties of the EQ-5D-5L utility index in patients after arthroscopic rotator cuff repair (RCR), total shoulder arthroplasty (TSA) or thumb carpometacarpal (CMC I) arthroplasty.

METHODS

In this prospective study, all patients completed the EQ-5D-5L before surgery and 6 months and 1 year after surgery. In addition, RCR patients completed the Oxford Shoulder Score (OSS), TSA patients completed the Shoulder Pain and Disability Index (SPADI) and CMC I patients completed the brief Michigan Hand Outcomes Questionnaire (brief MHQ) at each designated time point. Construct validity (Pearson's correlation coefficient, r), responsiveness (effect size), minimal important difference (MID), minimal important change (MIC), and floor and ceiling effects of the EQ-5D-5L were determined. To test discriminative ability, EQ-5D-5L utility indices of patients who were in a patient acceptable symptom state (PASS) or not at follow-up were compared using the Mann-Whitney U test.

RESULTS

We included 153 RCR, 150 TSA, and 151 CMC I patients. The EQ-5D-5L utility index correlated with the OSS (r = 0.73), SPADI (r = - 0.65) and brief MHQ (r = 0.61). The effect sizes were 1.3 (RCR and CMC I group) and 1.1 (TSA). The MID and MIC ranged from 0.027 to 0.209. Ceiling effects were found. The EQ-5D-5L utility index differed significantly between patients being in a PASS versus patients who were not in a PASS.

CONCLUSION

The EQ-5D-5L utility index shows good construct validity, responsiveness and discriminative ability in patients after arthroscopic RCR, TSA and CMC I arthroplasty and is suitable to quantify quality of life.

CLINICAL TRIAL REGISTRATION

This auxiliary analysis is part of a primary study that was originally registered at ClinicalTrials.gov (NCT01954433) on October 1, 2013.

Patient-acceptable symptom states in myasthenia gravis

Objectives

To estimate patient-acceptable symptom state (PASS) cut points for myasthenia gravis (MG) health scales.

Methods

We conducted an electronic survey that included the Myasthenia Gravis Impairment Index (MGII), EuroQol 5-Dimension (EQ5D), and a simple PASS question. PASS-anchored thresholds were estimated for the MGII questionnaire through receiver operating characteristic curves. We used the MGII PASS cut point in a validation cohort of 257 patients to estimate PASS thresholds for other clinically relevant health scales such as the Quantitative Myasthenia Gravis Scale (QMGS), Myasthenia Gravis Activities of Daily Living (MG-ADL), Myasthenia Gravis Composite (MGC), and Myasthenia Quality of Life (MG-QoL15).

Results

One hundred twenty-four of ≈250 invited patients answered the electronic survey (49% response rate), and 80 considered their current symptom state acceptable (PASS-positive). They had lower MGII scores than PASS-negative patients (7.76 ± 9.37 vs 25.0 ± 13.7, p < 0.0001) and better EQ5D scores (0.86 ± 0.17 vs 0.69 ± 0.18, p < 0.0001). The MGII questionnaire threshold for PASS was ≤10 points. With the use of this threshold in an independent dataset of 257 patients, all patients in remission or minimal manifestation status were PASS-positive. In addition, some patients in Classes I, II, and IIIA also achieved PASS status. PASS thresholds for the QMGS, MG-ADL, MGC, and MG-QoL15 were ≤7, 2, 3, and 8 points, respectively.

Conclusions

We have estimated thresholds for commonly used myasthenia health scales reflecting patient-acceptable states in patients with MG. These thresholds indicate a global state of well being, rather than a change in scores, or being better. Therefore, PASS thresholds can be used as secondary endpoints for myasthenia research.

Clinical thresholds of symptoms for deciding on surgery for trapeziometacarpal osteoarthritis

The severity of preoperative symptoms at which patients are likely to achieve a minimal important change and patient acceptable symptom state after surgery may help the decision to perform surgery for trapeziometacarpal osteoarthritis. The study objective was to define these thresholds for pain at rest and during activities as well as for the brief Michigan Hand Outcomes Questionnaire. One hundred and fifty-one patients were examined before surgery and 3, 6 and 12 months after surgery. The minimal important change after surgery was 1.9, 3.9 and 16 scores for pain at rest, pain during activities and the brief Michigan Hand Outcomes Questionnaire, respectively. The respective patient acceptable symptom state values were 1.5, 2.5 and 70 after surgery. Our results show that patients with baseline pain values between 3.5 and 5.5 at rest, between 6.5 and 7.5 during activities and a presurgery brief Michigan Hand Outcomes Questionnaire score of about 47, have the greatest chance of achieving a relevant symptom change and an acceptable symptom state. The information from this study may help surgeons in deciding the surgical indications and help patients in their expectation in symptom relief after surgery. Level of evidence: IV.