Do severity measures explain differences in length of hospital stay? The case of hip fracture.

OBJECTIVE: To examine whether judgments about hospital length of stay (LOS) vary depending on the measure used to adjust for severity differences. DATA SOURCES/STUDY SETTING: Data on admissions to 80 hospitals nationwide in the 1992 MedisGroups Comparative Database. STUDY DESIGN: For each of 14 severity measures, LOS was regressed on patient age/sex, DRG, and severity score. Regressions were performed on trimmed and untrimmed data. R-squared was used to evaluate model performance. For each severity measure for each hospital, we calculated the expected LOS and the z-score, a measure of the deviation of observed from expected LOS. We ranked hospitals by z-scores. DATA EXTRACTION: All patients admitted for initial surgical repair of a hip fracture, defined by DRG, diagnosis, and procedure codes. PRINCIPAL FINDINGS: The 5,664 patients had a mean (s.d.) LOS of 11.9 (8.9) days. Cross-validated R-squared values from the multivariable regressions (trimmed data) ranged from 0.041 (Comorbidity Index) to 0.165 (APR-DRGs). Using untrimmed data, observed average LOS for hospitals ranged from 7.6 to 23.9 days. The 14 severity measures showed excellent agreement in ranking hospitals based on z-scores. No severity measure explained the differences between hospitals with the shortest and longest LOS. CONCLUSIONS: Hospitals differed widely in their mean LOS for hip fracture patients, and severity adjustment did little to explain these differences.     

Rural Implications of Medicare''s Post-Acute-Care Transfer Payment Policy

CONTEXT: Under the Medicare post-acute-care (PAC) transfer policy, acute-care hospitals are reimbursed under a per-diem formula whenever beneficiaries are discharged from selected diagnosis-related groups (DRGs) to a skilled nursing facility, home health care, or a prospective payment system (PPS)-excluded facility. Total per-diem payments are below the full DRG payment only when the patient's length of stay (LOS) is short relative to the geometric mean LOS for the DRG; otherwise, the full DRG payment is received. This policy originally applied to 10 DRGs beginning in fiscal year 1999 and was expanded to additional DRGs in FY2004. The Secretary may include other DRGs and types of PAC settings in future expansions. PURPOSE: This article examines how the initial policy change affected rural and urban hospitals and investigates the likely impact of the FY2004 expansion and other possible future expansions. METHODS: The authors used 1998-2001 Medicare Provider Analysis and Review (MEDPAR) data to investigate changes in hospital discharge patterns after the original policy was implemented, compute the change in Medicare revenue resulting from the payment change, and simulate the expected revenue reductions under expansions to additional DRGs and swing-bed discharges. FINDINGS: Neither rural nor urban hospitals appear to have made a sustained change in their discharge behavior so as to limit their exposure to the transfer policy. Financial impacts from the initial policy were similar in relative terms for both types of hospitals and would be expected to be fairly similar for an expansion to additional DRGs. On average, including swing-bed discharges in the transfer policy would have a very small financial impact on small rural hospitals; only hospitals that make extensive use of swing beds after a short inpatient stay might expect large declines in total Medicare revenue. CONCLUSION: Rural hospitals are not disproportionately harmed by the PAC transfer policy. An expanded policy may even benefit rural hospitals by recognizing their lower use of post-acute-care and readjusting DRG weights so that they are paid more appropriately when providing the full course of inpatient care.     

Insurance aspects of DRG outlier payments.

As part of the prospective payment system, the government pays 'outlier' payments for especially long or expensive cases. These payments can be viewed as insurance for the hospital against excessive losses. They mitigate problems of access and underprovision of care for the sickest patients, and provide additional payments to the hospitals that take care of them, thereby making payments to hospitals more equitable. This paper characterizes the outlier payment formulae that minimize risk for hospitals under any fixed constraints on the sum of outlier payments and minimum hospital coinsurance rate. We then simulate per-case payments for a policy that did not include any outlier payments, the current outlier policy, and several other policies that minimize risk subject to different coinsurance constraints. The current outlier policy achieves each of its goals to at least some extent, but more insurance could be provided without lessening attainment of the other goals. We also discuss some problems with the implementation of the current policy, such as its reliance on day outliers.     

由后付制向预付制转变对医生行为影响的实验研究

目的:利用经济学实验探究按服务项目付费(FFS)和按疾病诊断相关分组付费(DRG)的激励对医生医疗服务供给行为的影响。方法:利用z-tree软件编程,招募120名临床相关专业的高年级本科生和研究生作为被试,测试其在FFS与DRG下为不同健康状况的患者选择提供的医疗服务数量。结果:总体上受试者在FFS(DRG)下提供的平均医疗服务量高(低)于最优服务量,差异有统计学意义。FFS下,受试者为健康状况好和中等的患者提供的平均医疗服务量分别为5.14、6.15,均高于最优服务量,在DRG下,受试者为健康状况好、中等、差的患者提供的平均医疗服务量分别比最优服务量少2.15%、10.73%、23.40%,差异有统计学意义。结论:FFS激励医生提供过量的医疗服务,DRG激励医生提供不足的医疗服务。FFS下医生对处于好和中等健康状况的患者过度服务,而DRG供给不足的程度随着患者疾病严重程度的增加而增加,且DRG下医生为健康状况好的患者提供的医疗服务量对患者最有利且医生所损失的净收益最少,对于健康状况中等和差的患者则相反。     

Insurance principles and the design of prospective payment systems.

This paper applies insurance principles to the issues of optimal outlier payments and designation of peer groups in Medicare's case-based prospective payment system for hospital care. Arrow's principle that full insurance after a deductible is optimal implies that, to minimize hospital risk, outlier payments should be based on hospital average loss per case rather than, as at present, based on individual case-level losses. The principle of experience rating implies defining more homogenous peer groups for the purpose of figuring average cost. The empirical significance of these results is examined using a sample of 470,568 discharges from 469 hospitals.     

Relevance of outlier cases in case mix systems and evaluation of trimming methods

Objectives: To determine the most appropriate outlier trimming method when the main source of information for case mix classification is length of stay (LOS) because cost information is unavailable. Methods: Discharges (35,262) from two public hospitals were analysed. LOS and cost outliers were calculated using different trimming methods. The agreement between cost and LOS trimming was analysed. Results: The trimming method using the geometric mean with two standard deviations (GM2) showed the highest level of agreement between cost and LOS and revealed the greatest proportion of extreme costs. Nearly 5% of cases were outliers, containing 16% of total LOS. This was the best approximation to 18% of extreme cost because when GM2 was applied to LOS, 88% of outlier cost was revealed. Conclusions: The methods were analysed because they are the most frequently used but the same methodology could be employed to compare other outlier determination methods. Outliers should be calculated because they ought to be valued differently from inlier cases.     

Beyond DRG: The effect of socio-economic indicators on inpatient resource allocation in Australia

Financing in Australia's public hospital works through the Australian Refined Diagnosis Related Groups (AR-DRGs) with separations to specific DRG groups based on medical diagnosis or surgical procedure, patient's age, mode of separation, clinical complexity and complications. This paper aims at assessing how the AR-DRGs reflect the efficiency and equity of the hospitals resource allocation. Using administrative data of all acute public hospital admissions and length of stay (LOS) as a proxy for hospital costs, this paper showed that patients’ socio-economic (SES) characteristics are a strong determinant of health care utilization. Our results revealed that the lower the SES, the longer the LOS and hence more utilization of the inpatient resources. Therefore, omitting SES from the risk adjusters list and solely focusing on DRG- based compensation penalizes hospitals catering to lower SES populations. Our findings further support the idea of smaller/remote hospitals based on block funding.     

Analysis of HIV/AIDS DRG in Portugal: a hierarchical finite mixture model

Inpatient length of stay (LOS) is an important measure of hospital activity, but its empirical distribution is often positively skewed, representing a challenge for statistical analysis. Taking this feature into account, we seek to identify factors that are associated with HIV/AIDS through a hierarchical finite mixture model. A mixture of normal components is applied to adult HIV/AIDS diagnosis-related group data (DRG) from 2008. The model accounts for the demographic and clinical characteristics of the patients, as well the inherent correlation of patients clustered within hospitals. In the present research, a normal mixture distribution was fitted to the logarithm of LOS and it was found that a model with two-components had the best fit, resulting in two subgroups of LOS: a short-stay subgroup and a long-stay subgroup. Associated risk factors for both groups were identified as well as some statistical differences in the hospitals. Our findings provide important information for policy makers in terms of discharge planning and the efficient management of LOS. The presence of “atypical” hospitals also suggests that hospitals should not be viewed or treated as homogenous bodies.     

Preparing for the G-DRG system: portfolio analysis of the hospitals in Saxony-Anhalt, Germany

Diagnosis-Related Groups are scheduled for step-by-step introduction into the German hospital system. Initially DRG base rates will be specific to each hospital (i. e. in keeping with the present budget), but eventually (by 2007) a common base rate will be reached in each federal state. This development may have grave financial consequences for some hospitals where initial base rates are above average and hence likely to be reduced. Therefore, we grouped the remunerations paid by the AOK Saxony-Anhalt (i. e. the largest statutory health insurance company in this federal state) for a total of 308,495 hospital cases in fiscal year 2000 according to hospital and diagnoses, expressed them as a percentage difference from the average remuneration, and analysed them jointly with the average length of stay (LOS). We found considerable differences between hospitals in terms of the payments per case and the LOS, independent of the stratification of the cases. For example, Magdeburg University Clinical Centre registered hospitalisations that were short (below average) but expensive (well above average), hence there is less scope for further rationalization of the LOS in this hospital compared to others. Considerable adjustments will become necessary in due course when switching over from hospital-specific base rates to a common regional base rate.     

Does Using Complementary Health Insurance Affect Hospital Length of Stay? Evidence from Acute Coronary Syndrome Patients

Background: Length of stay (LOS) is used as an indicator to show the efficacy of hospitals. An increase in hospitalized days is not cost effective and decreases the efficacy of hospitals. Using insurance has some side effects. One of these side effects is increasing the LOS. In this study we attempt to discover the effects of complementary health insurance (CHI) on LOS in patients with acute coronary syndrome (ACS). Methods: In this cross-sectional study, 260 patients were surveyed. By using Poisson regression, the effects of using complementary health insurance on LOS were examined. The effects of confounders were also controlled in the model. Results: The results of this study demonstrated that the relationship between use of CHI and LOS is direct. In addition, an increase in age and income also increases the LOS. The average LOS was 4.13 days, while it was 5.31 for CHI users, and 3.81 for CHI nonusers. Conclusion: Government budget is restricted and ACS treatments are costly. Decreasing LOS in ACS patients can help to spend the budget more effectively.     

Assessment of the introduction of DRG-based reimbursement in Switzerland: Evidence on the short-term effects on length of stay compliance in university hospitals

The implementation of a nationwide diagnosis-related groups (DRG) reimbursement system in 2012 marked an important step in increasing the transparency and efficiency of hospital services in Switzerland. However, no clear evidence exists to date on the response of hospitals to the introduction of SwissDRG. Using administrative data on inpatient stays in Swiss university hospitals and the length of stay compliance (LOSC) as a measure of hospital performance, we find a significant short-term reduction in LOSC for hospitals that experienced a change from retrospective per diem to prospective DRG reimbursement, compared to hospitals with a prospective payment system already before 2012. LOSC can be interpreted as a performance indicator because it compares the actual length of stay with a benchmark value, taken from the yearly DRG catalogue. The reduction in LOSC implies that hospitals in the treatment group on average had an increase in LOS relative to the benchmark compared to the control hospitals. This may be interpreted as a negative effect of SwissDRG on hospital performance, at least in the short-run, and we provide supporting evidence that hospitals that worked under DRG already before adapted more quickly and efficiently.     

Relationship between hospital structural level and length of stay outliers. Implications for hospital payment systems

BACKGROUND: Hospital structural level has been suggested as a factor that could explain part of the resource use variation left unexplained by diagnosis related groups (DRGs). However, the relationship between hospital structural level and the presence of cases of extreme resource use (outliers) is not known. Some prospective payment systems pay these cases separately. OBJECTIVES: To analyze the relationship between different hospital structural levels, defined according to hospital size, teaching activity and location, and the presence of length of stay (LOS) outliers. RESEARCH DESIGN: A logit model was used to analyze the patient discharge records of the acute care public hospitals' Minimum Data Set in Catalonia (Spain) in 1998. The final population contained 631,096 discharges grouped in 329 adjacent DRGs. MEASURES: LOS outliers were defined as cases with a LOS exceeding the geometric mean plus two standard deviations of all the stays in the same DRG. The 64 public hospitals of the Catalan health system were classified into large urban teaching hospitals, medium-sized teaching and community hospitals, and small community hospitals according to their structural complexity. The model also controlled for patient and health care process characteristics. RESULTS: Outliers accounted for 4.5% of total discharges distributed as follows: large urban teaching hospitals (5.6%), medium-sized teaching and community hospitals (4.6%), small community hospitals (3.6%). The probability of a patient being an outlier was higher in hospitals with greater structural complexity: large urban teaching hospitals (OR = 1.59), medium teaching and community hospitals (OR = 1.30) and small community hospitals (OR = 1). Adjustment through the control variables reduced differences among hospitals: large urban teaching hospitals (OR = 1.32), medium-sized teaching and community hospitals (OR = 1.22), and small community hospitals (OR = 1), but the differences remained significant (P < 0.01). CONCLUSIONS: Hospital structural level influences the presence of outliers even when controlling for patient and process characteristics. Thus, some outliers are due to hospital structural level and are not justified by patient characteristics.     

四川省三级医院慢性阻塞性肺疾病患者参加医疗保险类型与其住院时间的关系——基于分位数回归模型的实证分析

目的:分析慢性阻塞性肺疾病(COPD)患者参加医疗保险类型与其住院时间的关系,对患者平均住院日的降低和医疗保险支付方式的完善提供参考。方法:利用2016年第四季度在四川省三级医院就诊的36329例COPD患者病案首页信息,采用分位数回归模型,分析患者不同参保方式与其住院天数的关系。结果:不同参保方式患者的住院时间存在统计学差异,且这种差异大部分是由参保方式不同造成的。全公费患者住院天数最长,新型农村合作医疗参保患者最短,这种差异随住院时间分位数的提高而变大。结论:不同参保方式的COPD患者住院时间存在差异。全公费和城镇职工医疗保险参保患者的住院天数相对更长的可能原因是医院过度提供医疗服务;新型农村合作医疗参保患者的住院时间最短,可能原因是医院将其住院床位转移给了全公费和城镇职工医疗保险患者;不同医疗保险主办方监管力度不同也可能是造成差异的原因。     

Does severity explain differences in hospital length of stay for pneumonia patients?

OBJECTIVES: In the USA, the role of patient severity in determining hospital resource use has been questioned since Medicare adopted prospective hospital payment based on diagnosis-related groups (DRGs). Exactly how to measure severity, however, remains unclear. We examined whether assessments of severity-adjusted hospital lengths of stay (LOS) varied when different measures were used for severity adjustment. METHODS: The complete study sample included 18,016 patients receiving medical treatment for pneumonia at 105 acute care hospitals. We studied 11 severity measures, nine based on patient demographic and diagnosis and procedure code information and two derived from clinical findings from the medical record. For each severity measure, LOS was regressed on patient age, sex, DRG, and severity score. Analyses were performed on trimmed and untrimmed data. Trimming eliminated cases with LOS more than three standard deviations from the mean on a log scale. RESULTS: The trimmed data set contained 17,976 admissions with a mean (S.D.) LOS of 8.9 (6.1) days. Average LOS ranged from 5.0-11.8 days among the 105 hospitals. Using trimmed data, the 11 severity measures produced R-squared values ranging from 0.098-0.169 for explaining LOS for individual patients. Across all severity measures, predicted average hospital LOS varied much less than the observed LOS, with predicted mean hospital LOS ranging from about 8.4-9.8 days. DISCUSSION: No severity measure explained the two-fold differences among hospitals in average LOS. Other patient characteristics, practice patterns, or institutional factors may cause the wide differences across hospitals in LOS.     

Factors influencing hospital high length of stay outliers

ABSTRACT: BACKGROUND: The study of length of stay (LOS) outliers is important for the management and financing of hospitals. Our aim was to study variables associated with high LOS outliers and their evolution over time. METHODS: We used hospital administrative data from inpatient episodes in public acute care hospitals in the Portuguese National Health Service (NHS), with discharges between years 2000 and 2009, together with some hospital characteristics. The dependent variable, LOS outliers, was calculated for each diagnosis related group (DRG) using a trim point defined for each year by the geometric mean plus two standard deviations. Hospitals were classified on the basis of administrative, economic and teaching characteristics. We also studied the influence of comorbidities and readmissions. Logistic regression models, including a multivariable logistic regression, were used in the analysis. All the logistic regressions were fitted using generalized estimating equations (GEE). RESULTS: In near nine million inpatient episodes analysed we found a proportion of 3.9 % high LOS outliers, accounting for 19.2 % of total inpatient days. The number of hospital patient discharges increased between years 2000 and 2005 and slightly decreased after that. The proportion of outliers ranged between the lowest value of 3.6 % (in years 2001 and 2002) and the highest value of 4.3 % in 2009. Teaching hospitals with over 1,000 beds have significantly more outliers than other hospitals, even after adjustment to readmissions and several patient characteristics. CONCLUSIONS: In the last years both average LOS and high LOS outliers are increasing in Portuguese NHS hospitals. As high LOS outliers represent an important proportion in the total inpatient days, this should be seen as an important alert for the management of hospitals and for national health policies. As expected, age, type of admission, and hospital type were significantly associated with high LOS outliers. The proportion of high outliers does not seem to be related to their financial coverage; they should be studied in order to highlight areas for further investigation. The increasing complexity of both hospitals and patients may be the single most important determinant of high LOS outliers and must therefore be taken into account by health managers when considering hospital costs.     

Assessing the FY 1989 change in Medicare PPS outlier policy

In fiscal year (FY) 1989, Medicare changed its rules for paying for extremely long or expensive hospital stays called "outliers." We compared outlier payments in FYs 1989 and 1988, after adjusting for other simultaneous policy changes. We found that the new policy succeeded in targeting more outlier payments to the most expensive cases and to the hospitals suffering larger prospective payment system (PPS) losses and in reducing hospital financial risk. Using time-series analyses, we show that the policy change had no measurable effect on the timing of discharges or on the concentration of expensive cases in urban government-owned hospitals.     

Socio-demographic patient profiles and hospital efficiency: does patient mix affect a hospital's ability to perform?

This study investigates whether inclusion of patient profiles impacts on the inferences drawn from measuring performance using patient level data. Performance is in this setting defined by resources used in treating patients in a given diagnose related group where use of resources is approximated by length of stay (LOS). The analysis is based on Danish registry data from 2006. Patient data include registry data on income, employment status and information on whether the patient receives benefits or lives alone. Considerable variation in the socio-demographic characteristics of patients across Danish hospitals was observed, and some patient characteristics were shown to drive the need for longer hospital stays beyond what is captured in DRG scores. Ranking of hospitals based on observed versus expected LOS remained largely unaffected when controlling for patient characteristics, suggesting that variation in LOS across hospitals is mainly driven by other factors than patients’ socio-demographic characteristics. Nevertheless, the results of this study indicate that the current Danish remuneration system discriminates hospitals that more often serve older patients and patients with a less developed social network. These hospitals tend to have a reduced turnover of patients and their ability to generate revenue is therefore constrained.     

Comments on HCFA hospital death rate statistical outliers. Health Care Financing Administration.

In March 1986, the Health Care Financing Administration (HCFA) released ten lists of death-rate "outlier" hospitals, one for all 1984 Medicare discharges and nine for specific DRGs. Recent Medicare hospital discharge abstracts have substantially undercounted in-hospital deaths, with large variations by state. Apart from the proportion of a hospital's cases in 80 DRGs, the predictive models had no measures of case severity based on diagnosis or procedure. Having DRG 123 (all deaths from acute myocardial infarction) as an independent variable in the all-death regression model probably accounted for much of its high r2. Inclusion of an independent variable for average length of stay (ALOS) favored hospitals in higher ALOS states by higher predicted death rates. Model bias also favored lower-risk hospitals. Small numbers of predicted deaths for specific DRGs limited low-volume hospitals on these outlier lists to those with high ratios of actual to predicted deaths. On six of the nine DRG-specific outlier lists, a total 1,222 hospitals had unfavorable residuals, while only 8 were favorable. Ten recommendations are given to increase reliability of future outcome analyses.     

不同医疗保障制度慢性乙肝患者住院床日数及出院转归影响因素分析

目的：分析不同医疗保障制度下慢性乙肝患者的住院床日数及出院转归的影响因素。方法：在山东省济南市和潍坊市共选择3所县级医院和3所市级医院,每所医院抽取2009年全部出院诊断为＂乙型肝炎＂的病历;采取描述性统计及多元线性回归分析数据。结果：城镇职工医保的各型慢性乙肝患者的平均住院床日数约为城镇居民医保患者的1.6～2.3倍,为新农合患者的1.5～1.9倍。医疗保障类型、医院级别、出院转归及慢性乙肝的分型对住院床日数的影响具有统计学意义;住院床日数影响出院转归。结论和建议：不同医疗保障制度间的待遇差异,导致了患者住院床日数的差异;住院床日数又影响了患者的病情转归。建议缩小和消除不同医疗保障制度间的不平等,保障国民健康权益的公平性。     

It's more than just Tenet. Analysis shows not-for-profit hospitals,including a cluster in New Jersey,also heavily rely on outlier payments

After using a loophole in the Medicare outlier payment program to fuel growth, Tenet Healthcare Corp. has found itself operating under a financial cloud. But the spotlight hasn't focused on many other hospitals and systems that have relied heavily on outlier payments to boost their bottom lines. At left, Saint Barnabas Medical Center in Livingston, N.J., ranks among hospitals with a high reliance on outlier payments.