美国布朗大学Momotazur Rahman团队对重症医院和非重症医院中诊断编码与风险校正后短期死亡率差异的相关性进行了分析。2020年8月4日，该研究发表在《美国医学会杂志》上。

偏远地区重症医院（CAH）为农村社区提供治疗。据报道，相对于非CAH，CAH的死亡率有所增加。由于医疗保险按成本补偿了CAH，因此CAH报告的诊断数要少于非CAH，这可能会影响风险校正后的结果比较。

在考虑诊断编码的差异后，为了评估CAH和非CAH之间风险校正后死亡率的系列差异，2007-2017年，研究组针对因肺炎、心力衰竭、慢性阻塞性肺疾病、心律不齐、尿路感染、败血病和中风而被美国CAH和非CAH收治的农村医疗保险付费服务受益人进行了一项系列横断面研究。

出院诊断计数包括2010-2011年的趋势，当时医疗保险扩大了住院患者的允许账单代码数量，并根据人口统计、初步诊断、既往情况校正了住院和出院后30天的综合死亡率。

2850194名受益人的平均年龄为76.3岁，55.5%为女性，共有4094720次住院（17%为CAH）。与非CAH相比，CAH患者年龄较大（中位年龄分别为80.1岁和76.8岁），且女性占比更高（分别为58%和55%）。

2010年，校正后的CAH平均出院诊断数为7.52，显著低于非CAH（8.53）。2011年，在编码诊断中，CAH平均出院诊断数为9.27，显著低于非CAH（12.27），且组间差异明显增大。

2007年，CAH组经有分级条件类别（HCC）的模型校正后的死亡率为13.52%，显著高于非CAH组（11.44%）；2017年分别增长至15.97%和12.46%，差异依然显著。除2007年和2010年之外，CAH组和非CAH组在没有HCC的模型校正后的死亡率在所有年份均无显著差异。

总之，对于2007-2017年住院的农村医疗保险受益人而言，CAH提交的医院诊断代码明显少于非CAH，且在大多数年份中，根据既往病情进行校正但未进行院内合并症措施校正的短期死亡率没有显著差异。该结果表明，考虑到医院合并症的不同编码方式，CAH的短期死亡率可能与非CAH相差不大。

附：英文原文

Title: Association of Diagnosis Coding With Differences in Risk-Adjusted Short-term Mortality Between Critical Access and Non–Critical Access Hospitals

Author: Cyrus M. Kosar, Lacey Loomer, Kali S. Thomas, Elizabeth M. White, Orestis A. Panagiotou, Momotazur Rahman

Issue&Volume: 2020/08/04

Abstract: 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 4094720 hospitalizations (17% CAH) for 2850194 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.

DOI: 10.1001/jama.2020.9935

Source: https://jamanetwork.com/journals/jama/article-abstract/2768976