Cannabis-Based Products for Chronic Pain: A Systematic Review: Annals of Internal Medicine: Vol 175, No 8

Background: Contemporary data are needed about the utility of cannabinoids in chronic pain. Purpose: To evaluate the benefits and harms of cannabinoids for chronic pain. Data Sources: Ovid MEDLINE, PsycINFO, EMBASE, the Cochrane Library, and Scopus to January 2022. Study Selection: English-language, randomized, placebo-controlled trials and cohort studies (≥1 month duration) of cannabinoids for chronic pain. Data Extraction: Data abstraction, risk of bias, and strength of evidence assessments were dually reviewed. Cannabinoids were categorized by THC-to-CBD ratio (high, comparable, or low) and source (synthetic, extract or purified, or whole plant). Data Synthesis: Eighteen randomized, placebo-controlled trials (n = 1740) and 7 cohort studies (n = 13 095) assessed cannabinoids. Studies were primarily short term (1 to 6 months); 56% enrolled patients with neuropathic pain, with 3% to 89% female patients. Synthetic products with high THC-to-CBD ratios (>98% THC) may be associated with moderate improvement in pain severity and response (≥30% improvement) and an increased risk for sedation and are probably associated with a large increased risk for dizziness. Extracted products with high THC-to-CBD ratios (range, 3:1 to 47:1) may be associated with large increased risk for study withdrawal due to adverse events and dizziness. Sublingual spray with comparable THC-to-CBD ratio (1.1:1) probably is associated with small improvement in pain severity and overall function and may be associated with large increased risk for dizziness and sedation and moderate increased risk for nausea. Evidence for other products and outcomes, including longer-term harms, were not reported or were insufficient. Limitation: Variation in interventions; lack of study details, including unclear availability in the United States; and inadequate evidence for some products. Conclusion: Oral, synthetic cannabis products with high THC-to-CBD ratios and sublingual, extracted cannabis products with comparable THC-to-CBD ratios may be associated with short-term improvements in chronic pain and increased risk for dizziness and sedation. Studies are needed on long-term outcomes and further evaluation of product formulation effects. Primary Funding Source: Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services. (PROSPERO: CRD42021229579)

Medicare Spending on Drugs With Accelerated Approval

Background: The U.S. Food and Drug Administration provides accelerated approval to drugs on the basis of surrogate end points deemed to be “reasonably likely” to predict clinical benefit. To receive full approval, drugs must complete a confirmatory trial. Although most accelerated approved drugs ultimately receive full approval, others remain on the market without full approval for many years, and some are withdrawn before full approval is granted. Until confirmatory trials are completed and full approval is granted, there is uncertainty surrounding each drug's clinical benefits. Objective: To estimate fee-for-service Medicare payments on accelerated approved drugs without full approvals. Design: Cross-sectional analysis. Setting: Fee-for-service Medicare Part B and Part D drug claims in 2019. Participants: Beneficiaries enrolled in Medicare Part B and Part D plans. Measurements: Medicare spending for drugs treating accelerated approved indications without full approval, beneficiary spending, and drug characteristics. Results: In 2019, 45 drugs associated with 69 accelerated approved indications lacked full approval. Of those, the fee-for-service Medicare program spent $1.2 billion on 36 drugs across 55 indications. Medicare beneficiaries had $209 million in out-of-pocket spending on these drugs. Oncology drugs represented 82% of these indications and 72% of the Medicare spending. Extrapolating to Medicare Advantage, total Medicare spending on these drugs in 2019 was $1.8 billion. Limitations: The study drugs may have clinical benefit and may come to receive full approval after this analysis. The algorithm used to identify accelerated approved indications is novel. Generalizability to other years is unclear. Conclusion: In 2019, fee-for-service Medicare spent $1.2 billion on accelerated approved drugs without full approval. Medicare should adjust incentives to encourage sponsors to complete confirmatory trials as soon as possible. Primary Funding Source: Laura and John Arnold Foundation.

Mortality and Morbidity in Mild Primary Hyperparathyroidism: Results From a 10-Year Prospective Randomized Controlled Trial of Parathyroidectomy Versus Observation

Background: Primary hyperparathyroidism (PHPT) is a common endocrine disorder associated with increased risk for fractures, cardiovascular disease, kidney disease, and cancer and increased mortality. In mild PHPT with modest hypercalcemia and without known morbidities, parathyroidectomy (PTX) is debated because no long-term randomized trials have been performed. Objective: To examine the effect of PTX on mild PHPT with regard to mortality (primary end point) and key morbidities (secondary end point). Design: Prospective randomized controlled trial. (ClinicalTrials.gov: NCT00522028) Setting: Eight Scandinavian referral centers. Patients: From 1998 to 2005, 191 patients with mild PHPT were included. Intervention: Ninety-five patients were randomly assigned to PTX, and 96 were assigned to observation without intervention (OBS). Measurements: Date and causes of death were obtained from the Swedish and Norwegian Cause of Death Registries 10 years after randomization and after an extended observation period lasting until 2018. Morbidity events were prospectively registered annually. Results: After 10 years, 15 patients had died (8 in the PTX group and 7 in the OBS group). Within the extended observation period, 44 deaths occurred, which were evenly distributed between groups (24 in the PTX group and 20 in the OBS group). A total of 101 morbidity events (cardiovascular events, cerebrovascular events, cancer, peripheral fractures, and renal stones) were also similarly distributed between groups (52 in the PTX group and 49 in the OBS group). During the study, a total of 16 vertebral fractures occurred in 14 patients (7 in each group). Limitation: During the study period, 23 patients in the PTX group and 27 in the OBS group withdrew. Conclusion: Parathyroidectomy does not appear to reduce morbidity or mortality in mild PHPT. Thus, no evidence of adverse effects of observation was seen for at least a decade with respect to mortality, fractures, cancer, cardiovascular and cerebrovascular events, or renal morbidities. Primary Funding Source: Swedish government, Norwegian Research Council, and South-Eastern Norway Regional Health Authority.

Preconception Antidiabetic Drugs in Men and Birth Defects in Offspring: A Nationwide Cohort Study: Annals of Internal Medicine: Vol 175, No 5

Background: Diabetes reduces semen quality and increasingly occurs during reproductive years. Diabetes medications, such as metformin, have glucose-independent effects on the male reproductive system. Associations with birth defects in offspring are unknown. Objective: To evaluate whether the risk for birth defects in offspring varies with preconceptional pharmacologic treatment of fathers with diabetes. Design: Nationwide prospective registry-based cohort study. Setting: Denmark from 1997 to 2016. Participants: All liveborn singletons from mothers without histories of diabetes or essential hypertension. Measurements: Offspring were considered exposed if their father filled 1 or more prescriptions for a diabetes drug during the development of fertilizing sperm. Sex and frequencies of major birth defects were compared across drugs, times of exposure, and siblings. Results: Of 1 116 779 offspring included, 3.3% had 1 or more major birth defects (reference). Insulin-exposed offspring (n = 5298) had the reference birth defect frequency (adjusted odds ratio [aOR], 0.98 [95% CI, 0.85 to 1.14]). Metformin-exposed offspring (n = 1451) had an elevated birth defect frequency (aOR, 1.40 [CI, 1.08 to 1.82]). For sulfonylurea-exposed offspring (n = 647), the aOR was 1.34 (CI, 0.94 to 1.92). Offspring whose fathers filled a metformin prescription in the year before (n = 1751) or after (n = 2484) sperm development had reference birth defect frequencies (aORs, 0.88 [CI, 0.59 to 1.31] and 0.92 [CI, 0.68 to 1.26], respectively), as did unexposed siblings of exposed offspring (3.2%; exposed vs. unexposed OR, 1.54 [CI, 0.94 to 2.53]). Among metformin-exposed offspring, genital birth defects, all in boys, were more common (aOR, 3.39 [CI, 1.82 to 6.30]), while the proportion of male offspring was lower (49.4% vs. 51.4%, P = 0.073). Limitation: Information on underlying disease status was limited. Conclusion: Preconception paternal metformin treatment is associated with major birth defects, particularly genital birth defects in boys. Further research should replicate these findings and clarify the causation. Primary Funding Source: National Institutes of Health.

Sodium–Glucose Cotransporter-2 Inhibitors in Patients With Heart Failure: A Systematic Review and Meta-analysis: Annals of Internal Medicine: Vol 175, No 6

Background: Randomized controlled trials established the cardiac protection of sodium–glucose cotransporter-2 (SGLT2) inhibitors among adults with type 2 diabetes. New evidence suggests that these results could extend to people without diabetes. Purpose: To evaluate the effect of SGLT2 inhibitors in patients with heart failure, regardless of the presence of type 2 diabetes. Data Sources: PubMed, Web of Science, Cochrane Library, and Embase (OVID interface). Study Selection: Eligible trials randomly assigned adults with heart failure to SGLT2 inhibitors or control. Data Extraction: Time-to-event individual patient data were reconstructed from published Kaplan–Meier plots; time-varying risk ratios (RRs) were calculated in half-, 1-, and 2-year time frames; and anticipated absolute benefits were calculated using simple models applying relative effects to baseline risks. Data Synthesis: Sodium–glucose cotransporter-2 inhibitors reduce hospitalization for heart failure by 37% (95% CI, 25% to 47%) at 6 months, 32% (CI, 20% to 42%) at 1 year, and 26% (CI, 10% to 40%) at 2 years (all high certainty) and reduce cardiovascular death by 14% (CI, 1% to 25%) at 1 year (high certainty). Nevertheless, low-certainty evidence did not indicate protection against all-cause death, kidney disease progression, or kidney failure. Anticipated absolute benefits are greater for patients treated in the first year and for those with poorer prognoses, such as those newly diagnosed with heart failure in the hospital. In addition, SGLT2 inhibitors doubled the risk for genital infections (RR, 2.69 [CI, 1.61 to 4.52]; high certainty). Limitation: Covariates were unavailable in meta-analyses with reconstructed individual patient data. Conclusion: Among people with heart failure, SGLT2 inhibitors reduce hospitalizations for heart failure regardless of the presence of diabetes; absolute benefits are most pronounced in first-year treatment and vary with prognostic factors. Clinicians should note the increased risk for genital infection in patients receiving SGLT2 inhibitors. Primary Funding Source: 1.3.5 Project for Disciplines of Excellence, West China Hospital of Sichuan University. (PROSPERO: CRD42021255544)

Development and Validation of the Summary Elixhauser Comorbidity Score for Use With ICD-10-CM–Coded Data Among Older Adults

Background: Older adults have many comorbidities contributing to mortality. Objective: To develop a summary Elixhauser (S-Elixhauser) comorbidity score to predict 30-day, in-hospital, and 1-year mortality in older adults using the 38 comorbidities operationalized by the Agency for Healthcare Research and Quality (AHRQ). Design: Retrospective cohort study. Setting: Medicare beneficiaries from 2017 to 2019. Patients: Persons hospitalized in 2018 (n = 899 844) and 3 disease-specific hospitalized cohorts. Measurements: Weights were derived for 38 comorbidities to predict 30-day, in-hospital, and 1-year mortality. The S-Elixhauser score was internally validated and calibrated. Individual Elixhauser comorbidity indicators (38 comorbidities), the modified application of the AHRQ-derived Elixhauser summary score, the Charlson comorbidity indicators (17 comorbidities), and the Charlson summary score were externally validated. The c-statistic was used to evaluate discrimination of a comorbidity score model. Results: The S-Elixhauser score was well calibrated and internally validated, with a c-statistic of 0.705 (95% CI, 0.703 to 0.707) in predicting 30-day mortality, 0.654 (CI, 0.651 to 0.657) for in-hospital mortality, and 0.743 (CI, 0.741 to 0.744) for 1-year mortality. In external validation of other comorbidity indices for 30-day mortality, the c-statistic was 0.711 (CI, 0.709 to 0.713) for the individual Elixhauser comorbidity indicators, 0.688 (CI, 0.686 to 0.690) for the AHRQ Elixhauser score, 0.696 (CI, 0.694 to 0.698) for the Charlson comorbidity indicators, and 0.690 (CI, 0.688 to 0.693) for the Charlson summary score. In 3 disease-specific populations, the discrimination of the S-Elixhauser score in predicting 30-day mortality ranged from 0.657 to 0.732. Limitation: Validation of the S-Elixhauser comorbidity score and head-to-head comparison with other comorbidity scores in an external population are needed to evaluate comparative performance. Conclusion: The S-Elixhauser comorbidity score is well calibrated and internally validated but its advantage over the AHRQ Elixhauser and Charlson summary scores is unclear. Primary Funding Source: National Institute on Aging.

SARS-CoV-2 Vaccine Antibody Response and Breakthrough Infection in Patients Receiving Dialysis

Background: Whether breakthrough SARS-CoV-2 infections after vaccination are related to the level of postvaccine circulating antibody is unclear. Objective: To determine longitudinal antibody-based response and risk for breakthrough infection after SARS-CoV-2 vaccination. Design: Prospective study. Setting: Nationwide sample from dialysis facilities. Patients: 4791 patients receiving dialysis. Measurements: Remainder plasma from a laboratory processing routine monthly tests was used to measure qualitative and semiquantitative antibodies to the receptor-binding domain (RBD) of SARS-CoV-2. To evaluate whether peak or prebreakthrough RBD values were associated with breakthrough infection, a nested case–control analysis matched each breakthrough case patient to 5 control patients by age, sex, and vaccination month and adjusted for diabetes status and region of residence. Results: Of the 4791 patients followed with monthly RBD assays, 2563 were vaccinated as of 14 September 2021. Among the vaccinated patients, the estimated proportion with an undetectable RBD response increased from 6.6% (95% CI, 5.5% to 7.8%) 14 to 30 days after vaccination to 20.2% (CI, 17.0% to 23.3%) 5 to 6 months after vaccination. Estimated median index values decreased from 91.9 (CI, 78.6 to 105.2) 14 to 30 days after vaccination to 8.4 (CI, 7.6 to 9.3) 5 to 6 months after vaccination. Breakthrough infections occurred in 56 patients, with samples collected a median of 21 days before breakthrough infection. Compared with prebreakthrough index RBD values of 23 or higher (equivalent to ≥506 binding antibody units per milliliter), prebreakthrough RBD values less than 10 and values from 10 to less than 23 were associated with higher odds for breakthrough infection (rate ratios, 11.6 [CI, 3.4 to 39.5] and 6.0 [CI, 1.5 to 23.6], respectively). Limitations: Single measure of vaccine response; ascertainment of COVID-19 diagnosis from electronic health records. Conclusion: The antibody response to SARS-CoV-2 vaccination wanes rapidly in persons receiving dialysis. In this population, the circulating antibody response is associated with risk for breakthrough infection. Primary Funding Source: Ascend Clinical Laboratory.

The Incidence of SARS-CoV-2 Reinfection in Persons With Naturally Acquired Immunity With and Without Subsequent Receipt of a Single Dose of BNT162b2 Vaccine: A Retrospective Cohort Study: Annals of Internal Medicine: Vol 175, No 5

Background: There is insufficient evidence regarding the magnitude and durability of protection conferred by a combined effect of naturally acquired immunity after SARS-CoV-2 infection and vaccine-induced immunity. Objective: To compare the incidence rate of SARS-CoV-2 reinfection in previously infected persons to that of previously infected persons who subsequently received a single dose of BNT162b2 messenger RNA vaccine. Design: A retrospective cohort study emulating a randomized controlled target trial through a series of nested trials. Setting: Nationally centralized database of Maccabi Healthcare Services, Israel. Participants: Persons with documented SARS-CoV-2 infection who did not receive subsequent SARS-CoV-2 vaccination were compared with persons with documented SARS-CoV-2 infection who received a single dose of the BNT162b2 vaccine at least 3 months after infection. Intervention: Forty-one randomized controlled trials were emulated, in which 107 413 Maccabi Healthcare Services' members aged 16 years and older were eligible for at least 1 trial. Measurements: SARS-CoV-2–related outcomes of infection, symptomatic disease, hospitalization, and death, between 2 March and 13 December 2021. Results: A statistically significant decreased risk (hazard ratio, 0.18 [95% CI, 0.15 to 0.20]) for reinfection was found among persons who were previously infected and then vaccinated versus those who were previously infected but remained unvaccinated. In addition, there was a decreased risk for symptomatic disease (hazard ratio, 0.24 [CI, 0.20 to 0.29]) among previously infected and vaccinated persons compared with those who were not vaccinated after infection. No COVID-19–related mortality cases were found. Limitation: Hybrid protection against non-Delta variants could not be inferred. Conclusion: Persons previously infected with SARS-CoV-2 gained additional protection against reinfection and COVID-19 from a subsequent single dose of the BNT162b2 vaccine. Nonetheless, even without a subsequent vaccination, reinfection appeared relatively rare. Primary Funding Source: None.

The Challenge of Genetic Variants of Uncertain Clinical Significance: A Narrative Review: Annals of Internal Medicine: Vol 175, No 7

Genomic tests expand diagnostic and screening opportunities but also identify genetic variants of uncertain clinical significance (VUSs). Only a minority of VUSs are likely to prove pathogenic when later reassessed, but resolution of the uncertainty is rarely timely. That uncertainty adds complexity to clinical decision making and can result in harms and costs to patients and the health care system, including the time-consuming analysis required to interpret a VUS and the potential for unnecessary treatment and adverse psychological effects. Current efforts to improve variant interpretation will help reduce the scope of the problem, but the high prevalence of rare and novel variants in the human genome points to VUSs as an ongoing challenge. Additional strategies can help mitigate the potential harms of VUSs, including testing protocols that limit identification or reporting of VUSs, subclassification of VUSs according to the likelihood of pathogenicity, routine family-based evaluation of variants, and enhanced counseling efforts. All involve tradeoffs, and the appropriate balance of measures is likely to vary for different test uses and clinical settings. Cross-specialty deliberation and public input could contribute to systematic and broadly supported policies for managing VUSs.

The Emperor Has No Ganey