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Background & objectives Race plays an important role in healthcare disparities, often resulting in worse health outcomes. It is unclear if other patient factors and race interactions may influence mortality in patients with COVID-19. We aimed to evaluate how multiple determinants of all-cause in-hospital mortality from COVID-19 were linked to race. Methods A retrospective observational study was conducted at two hospitals in metropolitan Detroit. We identified patients aged ≥18 years-old who had tested positive for COVID-19 and were admitted between March 9 through May 16, 2020. Multivariable logistic regression was performed assessing predictors of all-cause in-hospital mortality in COVID-19. Results We identified 1064 unique patients; 74% were African Americans (AA). The all-cause in-hospital mortality was 21.7%, with the majority of deaths seen in AA (65.4%, P = 0.002) and patients 80 years or older (52%, P < 0.0001). AA women had lower all-cause mortality than AA men, white women, and white men based on race-gender interactions. In multivariable logistic regression analysis, older age (>80-year-old), dementia, and chronic kidney disease were associated with worse all-cause in-hospital mortality. Adjusted for race and body mass index (BMI), the main odds ratios (OR) and 95% confidence intervals (CI) are: Age 80 and older vs < 60 in females: OR = 7.4, 95% CI: 2.9, 18.7; in males OR = 7.3, 95% CI: 3.3, 16.2; Chronic Kidney Disease (CKD): OR = 1.7, 95% CI: 1.2, 2.6; Dementia: OR = 2.2, 95% CI: 1.5, 3.3. Conclusion Gender significantly modified the association of race and COVID-19 mortality. African American females had the lowest all-cause in-hospital mortality risk compared to other gender-race groups.

Interlocking nails coated with antibiotic-supplemented cement provide effective treatment of infected long bone nonunion, but the thicker coating on guidewires may provide greater antibacterial activity. This study compared the properties of cement cured on each construct by evaluating 2-cm segments of 8-mm interlocking nails and 3.5-mm guidewires coated with antibiotic-supplemented cement. Each construct (n=7 for each group) was coated with polymethylmethacrylate cement (Simplex; Stryker Orthopaedics, Mahwah, New Jersey) containing either 1 g tobramycin or 1 g vancomycin powder plus 2.2 g tobramycin powder. A No. 40 French polyvinyl chloride chest tube was used as a mold for all constructs. Segments were soaked in sterile phosphate-buffered saline, and entire aliquots were exchanged at various intervals over a 6-week period. Antibiotic concentration, antibacterial activity, cement curing temperature, and porosity were measured. At least half of the total elution of antibiotics occurred within the first 24 hours for all constructs. For the tobramycin-only cement, no differences between constructs were observed. For constructs containing both antibiotics, interlocking nails showed more antibiotic release than guidewires at most time points (P<.05-P<.001). Antibiotics were released for 6 weeks and continued to inhibit Staphylococcus aureus growth. Cement curing temperatures for interlocking nails were lower than those for guidewires (P<.05). Guidewires coated with cement containing tobramycin and vancomycin showed significantly greater porosity compared with the other 3 groups (P<.05), but the amount of antibiotic released did not directly relate to porosity for any construct type. Interlocking nails coated with antibiotic-supplemented cement may provide greater antibiotic delivery to infected long bone nonunion compared with guidewires. A thin mantle of cement may allow greater elution, possibly as a result of cooler exothermic reactions. [Orthopedics. 2017; 40(3):e436-e442.].

We previously showed that strontium-doped calcium polyphosphate (SCPP) scaffold with poly(vinyl alcohol) (PVA) coating extended the impregnated erythromycin (EM) release. In this study, we examined the bactericidal effect of EM-doped SCPP (SCPP(EM) ) scaffolds with PVA coating in a Staphylococcus aureus (S. aureus) infected mouse pouch. SCPP scaffolds with or without 5% EM, and SCPP(EM) scaffolds coated with PVA (with or without 5% EM) were prepared. Scaffolds were implanted in the pouch of BALB/c mice, followed by inoculation of 1 × 10(3) colony-forming units of S. aureus. Mice were sacrificed 14 days after surgery. Pouch tissues and scaffolds were collected for histology, scanning electron microscopy, and microbiological analysis. In the absence of SCPP scaffolds, the pouch infection was eliminated by the host immune surveillance. In the presence of SCPP scaffolds, both the pouch tissues and scaffolds were infected, but SCPP(EM) scaffolds successfully inhibited bacterial growth. Although PVA coating of SCPP(EM) scaffolds enhanced bacterial growth, incorporation of EM into PVA coating inhibited growth. In conclusion, BALB/c mice were capable of eradicating a low grade S. aureus infection. SCPP protected S. aureus growth from host immune surveillance. Though PVA coating sustained EM release in vitro, it was unable to inhibit bacterial growth because PVA gel matrix provided a temporary shelter for bacteria to grow and slowed the EM release from SCPP scaffold. To guarantee a sufficient inhibition of bacterial growth at the initial stage, embedding EM or other antibiotics in the PVA coating is also essential.