Preferred language was not associated with regional anesthesia use after multilevel multivariable adjustment (OR 0.93) for total joint arthroplasty

Description #

After adjustment in a multilevel multivariable logistic regression (with a random intercept for anesthesiologist), preferred language was not significantly associated with regional anesthesia use: the odds ratio for LEP ("Other") versus English was 0.93 (95% CI, 0.52–1.67; P = .810), i.e. the confidence interval crosses 1 (Figure). In the same model, RA use was associated with age, sex, race, BMI, insurance, year of surgery, ASA class, and surgical disposition (see source inconsistency note), but not with language.

"After adjustment, there was no significant difference in RA use among languages, OR 0.93 [95% confidence interval {CI}, 0.52–1.67, P = .810]." (Sabra, 2025, p. 995)

"Language: Other vs English … 0.93 (0.52 to 1.67)" (Sabra, 2025, p. 995, Figure)

Methods Context #

What? #ⓘ

The observable: regional anesthesia utilization, modeled as the binary dependent variable, with preferred language (English/LEP) as the exposure of interest.

"A multilevel multivariable logistic regression was used to measure the association between preferred language (English/LEP) and RA utilization." (Sabra, 2025, p. 993)

How? #ⓘ

Multilevel (mixed-effects) multivariable logistic regression with a random intercept for the treating anesthesiologist, adjusting for demographic, comorbidity, and operative covariates; odds ratios with 95% CIs reported (SAS 9.4 and R 4.3.1; P < .05 significant).

"A random intercept was included to account for anesthesiologist correlation of anesthesia use." (Sabra, 2025, p. 993)

Who? #ⓘ

The full cohort of 58,918 patients aged >18 undergoing primary elective unilateral THR/TKR at HSS (2016–2023); English speakers were 57,520 (97.6%).

"We identified 58,918 patients undergoing a total joint arthroplasty from 2016 to 2023 with 58,211 (98.8%) underwent their procedure with RA (Table). English speakers accounted for 57,520 (97.6%)." (Sabra, 2025, p. 995)

Other Notes #

Source inconsistency: the Results text states the model showed "increased odds of RA use with … sex (female), race (Asian) … insurance (public)," but the Figure's own 95% CIs for Male-vs-Female (0.96, 0.81–1.12), Asian-vs-White (1.43, 0.72–2.81), and Medicaid/Medicare-vs-Commercial (0.81, 0.65–1.62) all cross 1 (not statistically significant). This over-reading concerns covariates, not the language exposure, which is unambiguously null.

Caveats #

• Retrospective single-institution EMR study with provider-bias variability and unmeasured cognitive impairment The findings come from a single-institution, retrospective EMR-based study at one specialized orthopedic hospital (HSS), which limits generalizability to centers with different patient populations, payer mixes, and RA practices. The authors also note variability in provider bias, and that they could not exclude patients with cognitive impairment because that variable was unavailable in the record — a potential uncontrolled confounder of both language documentation and anesthetic decision-making. Interpreter use and modality were captured only as documented in the EMR, which may undercount actual language-service use.
• Underpowered to detect the small observed language effect despite large sample (post hoc power) Despite the large overall sample (58,918 patients), the study is by the authors' own post hoc assessment underpowered to detect the small, non-significant language effect it observed. The design targets clinically meaningful differences of ≥2%; a true difference smaller than that (or concentrated in the tiny LEP subgroup) could be overlooked. This is the central interpretive caveat on all of the null language findings: absence of a detected association is not evidence of no association. The authors caution the results should be interpreted cautiously and note that post hoc power calculations are not recommended for definitive conclusions.
• Near-universal regional anesthesia creates a ceiling effect with only 13 non-RA LEP patients [Inferred:] Because regional anesthesia was near-universal at this institution (98.8% of 58,918 patients), the "did not receive RA" outcome group is only 707 patients, and the LEP patients within it number just 13. With so few LEP non-RA events, there is almost no outcome variance in which a language-based disparity could be detected — a ceiling/floor effect that limits both the univariate and adjusted analyses regardless of the total sample size. The null language association is therefore weak evidence of true equivalence and may not transfer to institutions where RA is not already the default. (This is my inference from the Table's cell counts, complementary to the authors' own power caveat.)