Time-Dependent Prediction Models for Individual Prognosis of Chronic Postsurgical Pain following Knee Replacement Based on an Extensive Multivariable Data Set

(1) Background: Clinically useful prediction models for chronic postsurgical pain (CPSP) in knee replacement (TKA) are lacking. (2) Methods: In our prospective, multicenter study, a wide-ranging set of 91 variables was collected from 933 TKA patients at eight time points up to one year after surgery. Based on this extensive data pool, simple and complex prediction models were calculated for the preoperative time point and for 6 months after surgery, using least absolute shrinkage and selection operator (LASSO) 1se and LASSO min, respectively. (3) Results: Using preoperative data only, LASSO 1se selected age, the Revised Life Orientation Test on pessimism, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-subscore pain and the Timed "Up and Go" Test for prediction, resulting in an area under the curve (AUC) of 0.617 and a Brier score of 0.201, expressing low predictive power only. Using data up to 6 months after surgery, LASSO 1se included preoperative Patient Health Questionnaire-4, Knee Injury and Osteoarthritis Outcome Score (KOOS)-subscore pain (pain) 3 months after surgery (month), WOMAC pain 3 and 6 months, KOOS subscore symptoms 6 months, KOOS subscore sport 6 months and KOOS subscore Quality of Life 6 months. This improved the predictive power to an intermediate one (AUC 0.755, Brier score 0.168). More complex models computed using LASSO min did little to further improve the strength of prediction. (4) Conclusions: Even using multiple variables and complex calculation methods, the possibility of individual prediction of CPSP after TKA remains limited.

Evaluation of Accuracy and Safety of the Next-Generation Up to 180-Day Long-Term Implantable Eversense Continuous Glucose Monitoring System: The PROMISE Study

Background: Use of continuous glucose monitoring (CGM) systems is being rapidly adopted as standard of care for insulin-requiring patients with diabetes. The PROMISE study (NCT03808376) evaluated the accuracy and safety of the next-generation implantable Eversense CGM system for up to 180 days. Methods: This was a prospective multicenter study involving 181 subjects with diabetes at 8 USA sites. All subjects were inserted with a primary sensor. Ninety-six subjects had a second sensor, either an identical sensor or a modified sensor (sacrificial boronic acid [SBA]), inserted in their other arm (53 and 43 subjects, respectively). Accuracy was evaluated by comparing CGM to YSI 2300 glucose analyzer (Yellow Springs Instrument [YSI]) values during 10 clinic visits (day 1-180). Confirmed event detection rates, calibration stability, sensor survival, and serious adverse events (SAEs) were evaluated. Results: For primary sensors, the percent CGM readings within 20%/20% of YSI values was 92.9%; overall mean absolute relative difference (MARD) was 9.1%. The confirmed alert detection rate at 70 mg/dL was 93% and at 180 mg/dL was 99%. The median percentage of time for one calibration per day was 56%. Sixty-five percent of the primary sensors survived to 180 days. For the SBA sensors, the percent CGM readings within 20%/20% of YSI values was 93.9%; overall MARD was 8.5%. The confirmed alert detection rate at 70 mg/dL was 94% and at 180 mg/dL was 99%. The median percentage of time for one calibration per day was 63%. Ninety percent of the SBA sensors survived to 180 days. No device- or insertion/removal procedure-related SAEs were reported. Conclusion: These data show the next-generation Eversense CGM system had sustained accuracy and safety up to 180 days, with an improved calibration scheme and survival, using the primary or SBA sensors.

Postoperative Infections Associated With Prolonged Spinal Cord Stimulation Trial Duration (PROMISE RCT)

Introduction

In the PROMISE study, a multinational randomized controlled trial (RCT) of the effectiveness of spinal cord stimulation (SCS) with multicolumn surgical leads as a treatment of low back pain, clinicians followed their usual practice. An early, unplanned safety analysis revealed that the infection rate in Belgium (5/23), where trial duration was a median 21.5 days, was significantly higher than the 1/64 rate observed in the other study countries (median 5.8 days, p < 0.01). This report reviews infections observed in the PROMISE study after study completion.

Materials and Methods

For all infections related to SCS, we used descriptive statistics and tests of independent variables to analyze potentially contributing factors (age, sex, coexisting medical conditions, tobacco use, lead type, and trial duration) between subjects with infections versus those without. Cumulative incidence curves were created using the Kaplan–Meier method and compared between the two strata using a log‐rank test.

Results

Among nine (5.2%) infections in 174 subjects trialed, the only significant contributing factor to infection was trial duration: median 21 days (range 3–56) for those with infection vs. six days (1–41) for those without (p = 0.001; Wilcoxon rank‐sum test). The cumulative incidence of infection for subjects trialed >10 days was 24.1% vs. 1.4% for subjects trialed ≤10 days (p < 0.001). After the protocol was amended to limit trial duration to 10 days, 14 infection‐free trials were performed in Belgium.

Conclusions

Although not part of the preplanned analysis, our observation supports the hypothesis of a cause‐effect relationship between trial duration and the risk of infection and the conclusion that prolonged SCS trials should be avoided.

Enrollment and transition challenges in the International Maternal Pediatric and Adolescent AIDS Clinical Trials (IMPAACT) network's PROMISE trial for resource-limited regions

BACKGROUND

We describe enrollment and accrual challenges in the "Promoting Maternal and Infant Survival Everywhere" (PROMISE) trial conducted in resource-limited countries, as well as the challenges in transitioning participants from the antepartum to the postpartum components of the study.

METHODS

PROMISE was a large multi-national randomized controlled trial of the safety and efficacy of interventions to reduce perinatal transmission of HIV-1 (HIV) during pregnancy and breastfeeding and of interventions to preserve maternal health after cessation of perinatal transmission risk. The PROMISE study included two protocols for HIV-infected pregnant women in resource-limited countries who intended to either breastfeed or formula-feed their infants and did not meet country criteria for antiretroviral treatment. The PROMISE breastfeeding protocol (1077BF) used a sequential randomization design with up to three randomizations (Antepartum, Postpartum, and Maternal Health). The PROMISE formula-feeding protocol (1077FF) had two randomizations (Antepartum and Maternal Health). Women presenting to the clinic during early or active labor or in the immediate postpartum period were registered as Late Presenters and screened to determine whether eligible to participate in the Postpartum randomization.

RESULTS

The study was conducted at 14 sites in seven countries and opened to enrollment in April 2011. A total of 3259 pregnant women intending to breastfeed and an additional 284 pregnant women intending to formula feed were randomized in the Antepartum component. A total of 204 Late Presenters were registered during labor or after delivery. Enrollment was high among breastfeeding women (representing 96% of the target of 3400 women) but was lower than expected among women intending to formula feed (28% of 1000 expected) and late-presenting women (8% of 2500 expected). The successful overall enrollment and final primary study analyses results were attributed to substantial preparation before the study opened, collaboration among all stakeholders, close study monitoring during implementation and the flexibility to change and streamline the protocol.

CONCLUSIONS

Experiences from the PROMISE study illustrate the challenges of enrolling in longer term studies in the setting of rapidly evolving prevention and treatment standards priorities. The lessons learned will help the community, site investigators, and study coordinators in the design and implementation of future clinical trials.