Importance Critical access hospitals (CAHs) provide care to rural communities. Increasing mortality rates have been reported for CAHs relative to non-CAHs. Because Medicare reimburses CAHs at cost, CAHs may report fewer diagnoses than non-CAHs, which may affect risk-adjusted comparisons of outcomes. Objective To assess serial differences in risk-adjusted mortality rates between CAHs and non-CAHs after accounting for differences in diagnosis coding. Design, Setting, and Participants Serial cross-sectional study of rural Medicare Fee-for-Service beneficiaries admitted to US CAHs and non-CAHs for pneumonia, heart failure, chronic obstructive pulmonary disease, arrhythmia, urinary tract infection, septicemia, and stroke from 2007 to 2017. The final date of follow-up was December 31, 2017. Exposure Admission to a CAH vs non-CAH. Main Outcomes and Measures Discharge diagnosis count including trends from 2010 to 2011 when Medicare expanded the allowable number of billing codes for hospitalizations, and combined in-hospital and 30-day postdischarge mortality adjusted for demographics, primary diagnosis, preexisting conditions, and with vs without further adjustment for Hierarchical Condition Category (HCC) score to understand the contribution of in-hospital secondary diagnoses. Results There were 4 094 720 hospitalizations (17% CAH) for 2 850 194 unique Medicare beneficiaries (mean [SD] age, 76.3 [11.7] years; 55.5% women). Patients in CAHs were older (median age, 80.1 vs 76.8 years) and more likely to be female (58% vs 55%). In 2010, the adjusted mean discharge diagnosis count was 7.52 for CAHs vs 8.53 for non-CAHs (difference, -0.99 [95% CI, -1.08 to -0.90]; P < .001). In 2011, the CAH vs non-CAH difference in diagnoses coded increased (P < .001 for interaction between CAH and year) to 9.27 vs 12.23 (difference, -2.96 [95% CI, -3.19 to -2.73]; P < .001). Adjusted mortality rates from the model with HCC were 13.52% for CAHs vs 11.44% for non-CAHs (percentage point difference, 2.08 [95% CI, 1.74 to 2.42]; P < .001) in 2007 and increased to 15.97% vs 12.46% (difference, 3.52 [95% CI, 3.09 to 3.94]; P < .001) in 2017 (P < .001 for interaction). Adjusted mortality rates from the model without HCC were not significantly different between CAHs and non-CAHs in all years except 2007 (12.19% vs 11.74%; difference, 0.45 [95% CI, 0.12 to 0.79]; P = .008) and 2010 (12.71% vs 12.28%; difference, 0.42 [95% CI, 0.07 to 0.77]; P = .02). Conclusions and Relevance For rural Medicare beneficiaries hospitalized from 2007 to 2017, CAHs submitted significantly fewer hospital diagnosis codes than non-CAHs, and short-term mortality rates adjusted for preexisting conditions but not in-hospital comorbidity measures were not significantly different by hospital type in most years. The findings suggest that short-term mortality outcomes at CAHs may not differ from those of non-CAHs after accounting for different coding practices for in-hospital comorbidities.

中文翻译：

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诊断编码与关键通路和非关键通路医院之间风险调整短期死亡率差异的关联

重要性 重症医院 (CAH) 为农村社区提供护理。据报道，相对于非 CAH，CAH 的死亡率增加。由于医疗保险按成本补偿 CAH，因此 CAH 报告的诊断可能少于非 CAH，这可能会影响结果的风险调整比较。目的 在考虑诊断编码的差异后，评估 CAH 和非 CAH 之间风险调整死亡率的连续差异。设计、设置和参与者对因肺炎、心力衰竭、慢性阻塞性肺病、心律失常、尿路感染、败血症和中风入院美国 CAH 和非 CAH 的农村医疗保险按服务收费受益人进行的系列横断面研究2007 年至 2017 年。随访的最终日期为 2017 年 12 月 31 日。 CAH 与非 CAH 的暴露入院。主要结果和措施 出院诊断计数，包括 2010 年至 2011 年医疗保险扩大住院计费代码的允许数量时的趋势，以及根据人口统计学、初步诊断、既往疾病和有与无的情况调整的住院和出院后 30 天死亡率进一步调整分层条件类别 (HCC) 评分以了解院内二级诊断的贡献。结果 2 850 194 名独特的医疗保险受益人（平均 [SD] 年龄，76.3 [11.7] 岁；55.5% 为女性）有 4 094 720 次住院治疗（17% CAH）。CAH 中的患者年龄较大（中位年龄为 80.1 岁与 76.8 岁）并且更可能是女性（58% 与 55%）。2010 年，CAH 的调整后平均出院诊断计数为 7.52，而非 CAH 为 8.53（差异，-0.99 [95% CI，-1.08 至 -0.90]；P < .001）。2011 年，编码诊断中 CAH 与非 CAH 的差异增加（CAH 与年份之间的相互作用 P < .001）至 9.27 与 12.23（差异，-2.96 [95% CI，-3.19 至 -2.73]；P < .001）。 001）。2007 年，根据 HCC 模型调整后的 CAH 死亡率为 13.52% 与非 CAH 的 11.44%（百分比差异，2.08 [95% CI，1.74 至 2.42]；P < .001），并增加至 15.97% 与 12.44。 %（差异，3.52 [95% CI，3.09 至 3.94]；P < .001）在 2017 年（交互作用 P < .001）。除 2007 年（12.19% 对 11.74%；差异，0.45 [95% CI，0.12 至 0.79]；P = 0.008）和 2010 年之外，所有年份 CAH 和非 CAH 的无 HCC 模型的调整死亡率没有显着差异（12.71% 与 12.28%；差异，0.42 [95% CI，0.07 至 0.77]；P = .02）。结论和相关性 对于 2007 年至 2017 年住院的农村医疗保险受益人，CAHs 提交的医院诊断代码明显少于非 CAHs，并且根据既往状况而不是住院合并症措施调整的短期死亡率在不同医院类型之间没有显着差异。大多数年。研究结果表明，在考虑了院内合并症的不同编码实践后，CAH 的短期死亡率结果可能与非 CAH 的结果没有差异。