In-hospital complications among survivors of admission for congestive heart failure, chronic obstructive pulmonary disease, or diabetes mellitus

Frequency and Impact of Infectious Disease Conditions Diagnosed During Decompensated Heart Failure Hospitalizations in the United States

There are limited data on the frequency of diagnosis of infectious disease and its impact on patients hospitalized with decompensated heart failure. We sought to evaluate the prevalence, types, trends, and outcomes of infectious disease diagnosis in patients admitted with decompensated heart failure. We performed a retrospective cohort study in patients admitted with a primary diagnosis of heart failure using the National Inpatient Sample database from 2009 to 2019. Patients with a length of stay ≥3 days were included. Patients with chronic dialysis, left ventricular assist devices, cardiogenic shock, or solid organ transplantation or who required mechanical ventilation or mechanical circulatory support were excluded. Patients were stratified according to the presence or absence of infectious disease diagnosis. Outcomes of interest were in-hospital mortality, length of stay, and resource utilization. Among the 7,228,521 admissions with a primary diagnosis of heart failure that met the inclusion and exclusion criteria, an infectious disease diagnosis was reported in 1,806,514 (24.9%). Infectious disease diagnosis was more frequent in patients who were female, older, and White, and who had higher baseline co-morbidity. Since 2014, there has been a steady decrease in infectious conditions in patients admitted with a primary diagnosis of heart failure (p for trend <0.01). After propensity match analysis was performed, patients with infectious disease diagnosis had a longer length of stay (6.9 vs 5.7 days, p <0.001) and higher cost ($14,305 vs $11,760, p <0.001), were less likely to be discharged home (35.3% vs 44.7%, p <0.001), and had higher in-hospital mortality (2.6% vs 1.6%, p <0.001). In conclusion, approximately 1 in 4 patients admitted with primary heart failure will be diagnosed with an infectious condition. The presence of an infectious disease diagnosis is associated with increased morbidity and mortality.

Bringing the hospital to home: Patient-reported outcome measures of a digital health-supported home hospitalisation platform to support hospital care at home for heart failure patients

Background

Hospitalisations for heart failure are frequent and costly, linked with a lower quality of life, and lead to higher morbidity and mortality. Home hospitalisation interventions could be a substitute for in-hospital stays to reduce the burden on patients. The current study aims to investigate patient-reported satisfaction and usability in combination with the safety of a digital health-supported home hospitalisation intervention for heart failure patients.

Methods

We conducted an international, multicentre, single-arm, interventional study to investigate the feasibility and safety of a digital health-supported home hospitalisation platform. Patients with acute decompensation of known and well-assessed chronic heart failure with an indication for hospital admission were included. The primary outcome was patient satisfaction. Secondary outcomes were usability, adherence, and safety.

Results

A total number of 66 patients were included, of which the data of 65 patients (98.5%) was analysed. A total of 86.1% of patients reported being very satisfied or totally satisfied. No patients reported to be not satisfied with the home hospitalisation intervention. The patients reported a sufficient usability score (mean score: 75.8% of 100%) for the digital health-supported home hospitalisation platform. The adherence to the daily measurements of blood pressure and weight was very high, whereas the adherence to the daily interaction with the eCoach was lower (69.3%). In 7 patients (10.8%), a conversion from home hospitalisation to regular hospitalisation was needed. Furthermore, 6 patients (9.2%) had rehospitalisation within 30 days after the end of the home hospitalisation intervention.

Conclusion

A digitally supported home hospitalisation intervention is feasible. This study demonstrates high patient satisfaction and sufficiently high usability scores. The safety outcomes are comparable with traditional heart failure hospitalisations. This indicates that digitally supported home hospitalisation could be an alternative to in-hospital care for all age groups, yet further research is needed to prove the (cost-) effectiveness.

Survival time to complications of congestive heart failure patients at Felege Hiwot comprehensive specialized referral hospital, Bahir Dar, Ethiopia

BACKGROUNDS

Congestive heart failure is a serious chronic condition when the heart's muscles become too damaged and a condition in which one or both ventricles cannot pump sufficient blood to meet the metabolic needs of the body. This study aimed to identify factors affecting the complications time of congestive heart failure patients treated from January 2016 to December 2019 at Felege Hiwot comprehensive specialized referral hospital in Bahir Dar, Ethiopia.

METHODS

A hospital-based retrospective data collection was collected from the medical charts of 218 randomly selected congestive heart failure patients. The Kaplan-Meier curve and the Cox proportional hazards model were used to compare and identify the factors associated with time to complication in patients with congestive heart failure.

RESULTS

The median complication time of congestive heart failure patients was 22 months [95% CI: 21.98-28.01]. About 194 (88.99%) of the patients were complicated. The Kaplan-Meier curve depicts the survival probability of complicated patients decreasing as the complication time increases. The hazard ratios for serum sodium concentration, left ventricular ejection fraction, patients from rural areas, age of patients, serum hemoglobin concentration, and New York heart association classes I, II, and III were given 0.94 [95% CI: 0.90-1.00], 0.74 [95% CI: 0.65-0.85], 0.75 [95% CI: 0.68-0.84], 1.28 [95% CI: 1.12-1.46], 0.89 [95% CI: 0.85-0.94], 0.44 [95% CI: 0.36-0.53], 0.54 [95% CI: 0.47-0.62] and 0.73 [95% CI: 0.65-0.81] respectively, and they are statistically associated with the complication time of congestive heart failure patients.

CONCLUSIONS

The median complication time of congestive heart failure patients was 22 months. This study strongly suggests that healthcare awareness should be strengthened earlier about the potential complications for patients with lower serum sodium concentrations below the threshold and aged congestive heart failure patients to reduce the risk of developing complications.

Asthma and delirium episodes during hospitalization

BACKGROUND

Delirium incidences during hospitalization are an important problem in elderly patients. The problem of delirium episodes in patients with obstructive disease during hospitalization was investigated.

MATERIAL AND METHODS

From a total of 37,156 subjects, the following were randomly selected: 32,261 patients with asthma, 4896 with chronic obstructive pulmonary disease (COPD), and 5455 without obstructive disease. Their ages ranged from 65-95 years, and they were hospitalized between 2006 and 2015. Delirium incidences were monitored based on the International Classification of Disease (ICD)-10 codes and medical documentation.

RESULTS

The delirium episodes during all hospitalizations were independently associated with asthma (odds ratio [OR] = 2.91, confidence interval [CI] = 1.62-5.84), with severe type of asthma (OR = 4.24, CI = 1.94-8.93), partim controlled asthma (OR = 3.1, CI = 1.29-8.46), and uncontrolled asthma (OR = 4.88, CI = 2.12-9.42). It was comparable with COPD as follows: all incidences of delirium during hospitalization (OR = 3.17, CI = 1.42-7.23) or severe COPD (III degree OR = 5.15, CI = 2.01-13.69). Elderly patients with asthma with uncontrolled or partially controlled asthma with a coincidence of advanced age, dementia, or smoking had a greater predisposition to delirium episodes, particularly after surgery. Additionally, delirium incidence caused death more frequently in patients with asthma than in those with COPD.

CONCLUSION

Elderly patients with asthma have a higher risk of delirium episodes during any hospitalization, and, frequently, it ends in death.

In-hospital death and adverse clinical events in elderly patients according to disease clustering: the REPOSI study

OBJECTIVE

The aim of the study was to recognize clusters of diseases among hospitalized elderly and to identify groups of patients at risk of in-hospital death and adverse clinical events according to disease clustering.

METHOD

This was a cross-sectional study conducted in 38 internal medicine and geriatric wards in Italy participating in the Registro Politerapie SIMI (REPOSI) study during 2008. The subjects were 1,332 inpatients aged 65 years or older. Clusters of diseases (i.e., two or more co-occurrent diseases) were identified using the odds ratios (OR) for the associations between pairs of conditions, followed by cluster analysis. Logistic regression models were used to evaluate the effect of disease clusters on in-hospital death and adverse clinical events.

RESULTS

A total of 86.7% of the patients were discharged, 8.3% were transferred to another hospital unit, and 5.0% died during hospitalization; 36.4% of the patients had at least one adverse clinical event. Patients affected by the clusters, including heart failure (HF) and either chronic renal failure (CRF) or chronic obstructive pulmonary disease, had a significant association with in-hospital death (OR, 4.3;95% confidence interval [CI], 1.6-11.5; OR, 2.9; 95% CI, 1.1-8.3, respectively), as well as patients affected by CRF and anemia (OR, 6.1; 95% CI, 2.3-16.2). The cluster including HF and CRF was also associated with adverse clinical events (OR, 3.5; 95% CI, 1.5-7.8). The effect of both HF and CRF and anemia and CRF on in-hospital death was additive.

CONCLUSION

Several groups of older patients at risk of in-hospital death and adverse clinical events were identified according to disease clustering. Knowledge of the relationship among co-occurring diseases may help developing strategies to improve clinical practice and preventative interventions.

Subintensive care unit for the elderly: a new model of care for critically ill frail elderly medical patients

OBJECTIVE

An increasing number of elderly patients are admitted to the hospital for critical diseases and the gap between supply and demand of intensive care resources is a growing problem. To meet this challenge, 4 beds in a 24-bed acute care for the elderly (ACE) medical unit were dedicated to a subintensive care unit (SICU). Severely ill elderly medical patients, requiring a higher level of care than provided in ordinary wards, are admitted. The aim of the study was to describe the characteristics of the setting and to discuss its usefulness based on data obtained after the first period of implementation.

METHODS

This article describes the development, management, economics and patient characteristics of the SICU. Patient care combines the ACE model with a highly specialised medical care. Patients admitted to the SICU are compared with patients treated in the ordinary ACE unit before the SICU opened. All patients received a multidimensional evaluation, including demographics, main diagnosis, number of chronic somatic diseases, Charlson index, APACHE II score, APACHE-APS subscore, number of currently administered drugs, serum albumin, cognitive status (Mini-Mental State Examination), depression (Geriatric Depression Scale) and functional status (basic and instrumental activities of daily living). Ward physicians performed assessment and collection of data.

RESULTS

During the first 16 months, 489 patients were admitted, 401 according to the selection criteria (60 +/- years and APACHE II score > or =5 and/or APACHE-APS score > or =3). Mean age was 78.1 years, mean APACHE II score 14.5 (moderate severity) and non-invasive mechanical ventilation was received by 87 (21.7%). The most common diagnoses were respiratory failure, cardiac disease and stroke. Mean length of stay in the SICU was 61.8 h, and 6.0 days in the hospital. Compared with ACE-unit patients admitted during 2002 (n=1380), SICU patients were obviously more seriously ill (APACHE II score 14.5 vs 6.7). When comparing patients of same illness severity (APACHE-APS score > or =3) (n=125), patients treated in the SICU had lower in-hospital mortality than those treated in the ordinary ACE ward (12.5 vs 19.2%). Only a few patients (3.5%) were transferred to the intensive care unit as a consequence of increased severity of illness.

CONCLUSIONS

The SICU is an innovative method to treat frail elderly patients with more severe conditions. Low hospital mortality compared with that of severe patients in the ACE unit supports the usefulness of this model. It could be implemented in medical units of large hospitals in order to give optimal care and advanced interventions to the frail elderly and to avoid intensive care unit overcrowding.

Evaluating the Patient Safety Indicators

BACKGROUND

The Patient Safety Indicators (PSIs), an administrative data-based tool developed by the Agency for Healthcare Research and Quality, are increasingly being used to screen for potential in-hospital patient safety problems. Although the Veterans Health Administration (VA) is a national leader in patient safety, accurate information on the epidemiology of patient safety events in the VA is still unavailable.

OBJECTIVES

Our objectives were to: (1) apply the AHRQ PSI software to VA administrative data to identify potential instances of compromised patient safety; (2) determine occurrence rates of PSI events in the VA; and (3) examine the construct validity of the PSIs.

METHODS

We examined differences between observed and risk-adjusted PSI rates in the VA, compared VA and non-VA PSI rates, and investigated the construct validity of the PSIs by examining correlations of the PSIs with other outcomes of VA hospitalizations.

RESULTS

We identified 11,411 PSI events in the VA nationwide in FY'01. Observed PSI rates per 1000 discharges ranged from 0.007 for "transfusion reaction" to 155.5 for "failure to rescue." There were significant, although small, differences between VA and non-VA risk-adjusted PSI rates. Hospitalizations with PSI events had longer lengths of stay, higher mortality, and higher costs than those without PSI events.

CONCLUSIONS

Our results suggest that the PSIs may be useful as a patient safety screening tool in the VA. Our PSI rates were consistent with the national incidence of low rates; however, differences between VA and non-VA rates suggest that inadequate case-mix adjustment may be contributing to these findings.

Gaps in the care of patients admitted to hospital with an exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Patients admitted to hospital because of an exacerbation of chronic obstructive pulmonary disease (COPD) are at high risk of adverse events. We evaluated the association between gaps in care and adverse events during the hospital stay and after discharge.

METHODS

We retrospectively reviewed the charts of 105 consecutive patients discharged from hospital between Jan. 1 and Dec. 31, 2001, with a diagnosis of COPD exacerbation. On the basis of published guidelines, prior studies and discussions with colleagues, we defined a care gap as having occurred if any of 9 important inpatient and 7 discharge-related processes of care did not take place correctly. Inpatient adverse events included worsening of condition after admission, transfer to a higher level of care, cardiac arrest and death. Discharge-related adverse events were defined as including readmission to the hospital, revisit to the emergency department or death within 30 days after discharge.

RESULTS

Of the 105 patients studied, 88 (84%) had at least 1 inpatient gap in care and 16 (15%) an inpatient adverse event; 2 of the 16 died. Patients who had an inpatient adverse event had more gaps in their care (2.0 v. 1.3 gaps, p = 0.004) and longer stays (16.4 v. 8.6 days, p = 0.007). There were 6 adverse events (frequency 38%) among the 16 patients with 3 or more gaps in their care, 6 adverse events (28%) among the 21 patients with 2 gaps, 1 adverse event (2%) among the 51 patients with 1 gap and 3 adverse events (18%) among the 17 patients with no gaps in their care (p = 0.001 for trend). Of the 103 patients discharged alive, 102 (99%) had at least 1 gap in discharge-related care, but we found no association between these gaps and adverse events within 30 days after discharge.

INTERPRETATION

Gaps in the inpatient care of patients with COPD exacerbation were common and were associated with inpatient adverse events. Gaps in discharge-related care were also common but were not associated with postdischarge adverse events.

Can administrative data be used to compare postoperative complication rates across hospitals?

BACKGROUND

Several quality assessment systems use administrative data to identify postoperative complications, with uncertain validity.

OBJECTIVES

To determine how accurately postoperative complications are reported in administrative data, whether accuracy varies systematically across hospitals, and whether serious complications are more consistently reported.

DESIGN

Retrospective cohort.

SUBJECTS

Nine hundred ninety-one randomly sampled adults who underwent elective lumbar diskectomies at 30 nonfederal acute care hospitals in California in 1990 to 1991. Hospitals with especially low or high risk-adjusted complication rates, and patients who experienced complications, were over sampled.

MEASURES

Postoperative complications were specified by reviewing medical literature and consulting clinical experts; each complication was mapped to ICD-9-CM. Hospital-reported complications were compared with our independent recoding of the same records.

RESULTS

The weighted sensitivity, specificity, and positive and negative predictive values for reported complications were 35%, 98%, 82%, and 84%, respectively. The weighted sensitivity was 30% for serious, 40% for minor, and 10% for questionable complications. It varied from 21% among hospitals with fewer complications than expected to 45% among hospitals with more complications than expected. Only reoperation, bacteremia/sepsis, postoperative infection, and deep vein thrombosis were reported with at least 60% sensitivity. Half of the difference in risk-adjusted complication rates between low and high outlier hospitals was attributable to reporting variation.

CONCLUSIONS

ICD-9-CM complications were underreported among diskectomy patients, especially at hospitals with low risk-adjusted complication rates. The validity of using coded complications to compare provider performance is questionable, even with careful efforts to identify serious events, although these results must be confirmed using more recent data.

Relationship between hospital length of stay and quality of care in patients with congestive heart failure

OBJECTIVE

To determine the relationship between hospital length of stay (LOS) and quality of care in patients admitted for congestive heart failure (CHF).

METHODS

This observational study was conducted in the medical wards of the Geneva University Hospitals, Geneva, Switzerland. A random sample of 371 patients was drawn from the 1084 patients discharged alive with a principal diagnosis of CHF between January 1997 and December 1998. Explicit criteria grouped into three scores were used to assess the quality of processes of care: admission work-up (admission score); evaluation and treatment during the stay (treatment score); and readiness for discharge (discharge score). The association between LOS and quality of care was analysed using linear regression with adjustment for clinical characteristics.

RESULTS

The mean proportion of criteria met were 80% for the admission score, 66% for the treatment score, and 76% for the discharge score. Mean (SD) LOS was 13.2 (8.8) days. The admission score was not associated with LOS, but the treatment score increased by 0.5% (95% CI 0.3 to 0.7; p < 0.001) with each additional day in hospital and the discharge score increased by 2.5% (95% CI 1.6 to 3.3; p < 0.001) per day from admission to day 10 but remained unchanged thereafter. Adjustment for potential confounders did not substantially modify these relationships.

CONCLUSIONS

In patients with CHF there is a significant association between LOS and the quality of the treatment provided, as well as with readiness for discharge. Appropriate reorganisation of processes of care should accompany attempts at reducing LOS to avoid detrimental effects on quality of care.

Can administrative data be used to ascertain clinically significant postoperative complications?

The purpose of this study is to assess whether postoperative complications can be ascertained using administrative data. We randomly sampled 991 adults who underwent elective open diskectomies at 30 nonfederal acute care hospitals in California. Postoperative complications were specified by reviewing medical literature and by consulting clinical experts. We compared hospital-reported ICD-9-CM data and independently recoded ICD-9-CM data with complications abstracted by clinicians using detailed criteria. Recoded ICD-9-CM data were more likely than hospital-reported ICD-9-CM data to capture true complications, when they occurred, but they also mislabeled more patients who never experienced clinically significant complications. This finding was most evident for mild or ambiguous complications, such as atelectasis, posthemorrhagic anemia, and hypotension. Overall, recoded ICD-9-CM data captured 47% and 56% of all mild and severe complications, respectively, whereas hospital-reported ICD-9-CM data captured only 37% and 44%, respectively, of all mild and severe complications. These findings raise questions about the validity of using administrative data to ascertain postoperative complications, even if coders are carefully hired, trained, and supervised. ICD-9-CM complication codes are more promising as a tool to help providers identify their own adverse outcomes than as a tool for comparing performance.

Prognostic judgments and triage decisions for patients with acute congestive heart failure

STUDY OBJECTIVES

To determine how well triage physicians judge the probability of death or severe complications that require treatment only available in an ICU to maintain life for patients with acute congestive heart failure (CHF).

DESIGN

Prospective cohort study.

SETTING

An urban university hospital, a Veteran's Administration hospital, and a community hospital.

PATIENTS OR PARTICIPANTS

Patients were those visiting the emergency department (ED) with acute CHF, excluding those who already required a treatment only available in an ICU to maintain life, and those with possible or definite myocardial infarction. Physician participants were those caring for the patients in the ED.

MEASUREMENTS AND RESULTS

We performed chart reviews to ascertain whether each patient died or had severe complications develop by 4 days. We collected judgments of the probability of this outcome from the physicians taking care of the study patients in the ED. The prevalence of death or severe complications was 43 per 1,032 patients (4.2%). The mean +/- SD of physicians' judgments of the probability of this outcome was 32.1 +/- 28.4%. A calibration curve that stratified these judgments by decile demonstrated that physicians consistently overestimated this probability (p < 0.01). Physicians' judgments were only moderately good at discriminating which patients would have the outcome (receiver operating characteristic curve area, 0.715). Patients admitted to an ICU received the highest average predicted probability (56.4%), followed by those admitted to a telemetry unit (34.1%), to a regular hospital ward (29.8%), and those sent home (17.9%.)

CONCLUSIONS

Physicians drastically overestimated the probability of a severe complication that would require critical care for patients with acute CHF who were candidates for ICU admission. Their judgments of this probability were associated with their triage decisions, as they should be according to several guidelines for ICU triage. Overestimation of the probability of severe complications may have lead to overutilization of scarce critical care resources. Current critical care triage guidelines should be revised to take this difficulty into account, and better predictive models for patients potentially requiring critical care should be developed.

Clinical profile and management of heart failure: rural community hospital vs. metropolitan heart center

BACKGROUND

Knowledge on clinical characteristics and prognosis of patients with heart failure originates from studies of selected populations in clinical trials or from epidemiological observations. Reports on the large numbers of patients with heart failure treated in community hospitals are sparse.

OBJECTIVE

Are there differences in patient characteristics and heart failure management between a metropolitan heart center (HC) and a rural community hospital (RCH)?

PATIENTS AND METHODS

Retrospective analysis of medical charts from all patients admitted for heart failure (ICD 428.x, NYHA II-IV, EF<45%) between May 1997 and April 1998 and discharged alive from a rural community hospital. A similar, but prospective registry was available at the HC. Follow-up information was obtained by request at registration authorities.

RESULTS

Patient groups comprised 120 in RCH and 146 in HC. Mean age was 75+/-11 and 66+/-11 years, respectively (P<0.001); 48% (RCH) vs. 74% (HC) of patients were male (P<0.001). On admission the proportion of functional class IV was 69% (RCH) vs. 17% (HC) (P<0.001). At discharge, the rate of ACE-inhibitors was 74% (RCH) vs. 98% (HC); 11% (RCH) vs. 43% (HC) of patients received beta-blocker therapy. Ninety-six percent of patients in HC underwent and 22% in RCH had undergone invasive diagnostics. One-year mortality rate of patients discharged alive was 26% in RCH and 19% in HC (P=n.s. after adjustment for age and gender).

CONCLUSION

Heart failure management according to current guidelines, using beta-blockers and ACE inhibitors, and invasive cardiac examination was significantly less performed in the rural community hospital than in the metropolitan heart center. Therefore, strategies to improve heart failure management according to guidelines are urgently needed.

Causes and consequences of comorbidity: a review

A literature search was carried out to identify and summarize the existing information on causes and consequences of comorbidity of chronic somatic diseases. A selection of 82 articles met our inclusion criteria. Very little work has been done on the causes of comorbidity. On the other hand, much work has been done on consequences of comorbidity, although comorbidity is seldom the main subject of study. We found comorbidity in general to be associated with mortality, quality of life, and health care. The consequences of specific disease combinations, however, depended on many factors. We recommend more etiological studies on shared risk factors, especially for those comorbidities that occur at a higher rate than expected. New insights in this field can lead to better prevention strategies. Health care workers need to take comorbid diseases into account in monitoring and treating patients. Future studies on consequences of comorbidity should investigate specific disease combinations.

The association of quality of care and occurrence of in-hospital, treatment-related complications

BACKGROUND

Little data exist supporting the association of quality of care and nonfatal adverse outcomes in hospitalized patients, yet those outcomes are routinely scrutinized in quality assessment efforts.

OBJECTIVE

To determine whether measurable differences in quality of care are associated with the occurrence of non-fatal, in-hospital, and treatment-related complications.

DESIGN

Retrospective cohort study.

SUBJECTS

A total of 2,268 patients who were discharged alive from 9 Southwestern Veterans Affairs Medical Centers with congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD) or diabetes mellitus.

MEASURES

Retrospective chart review was performed to collect information on patient severity of illness, in-hospital complication occurrence, and process quality of care. Process quality was assessed as the adherence scores for admission work-up and for treatment during the hospital stay. Process quality represents the proportion of applicable admission or treatment criteria that were met by that patient's care providers. Once severity of illness was taken into account Cox proportional hazards regression was used to assess the independent contribution of process quality of care to complication occurrence.

RESULTS

Higher admission work-up adherence scores for COPD patients and higher treatment adherence scores for COPD and diabetes patients were associated with a lower risk of complication occurrence. The adjusted risk ratios of complications for higher versus lower adherence scores (with 95% CI) were 0.64 (0.43, 0.97) and 0.52 (0.33, 0.80) for admission and treatment, respectively, in COPD patients, and 0.51 (0.31, 0.83) for treatment in diabetics. No significant association was found in CHF patients.

CONCLUSION

Better admission work-up and treatment quality in COPD patients, as well as treatment quality in diabetic patients, are associated with lower risk of nonfatal treatment-related complications in the study population.

International Classification of Diseases, 9th Revision, Clinical Modification codes in discharge abstracts are poor measures of complication occurrence in medical inpatients

OBJECTIVES

The authors tested the ability of International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes in discharge abstracts to identify medical inpatients who experienced an in-hospital complication, using complications identified through chart review as the gold standard.

METHODS

Two sets of ICD-9-CM codes were used: an inclusive set including many medical diagnoses that may also be coexistent complicating conditions on admission rather than complications and an exclusive set consisting primarily of ICD-9-CM-specified complication and adverse drug event codes.

RESULTS

Neither set performed well as a diagnostic test for complication occurrence according to receiver operating characteristic analysis (ROC areas were 0.61 for the inclusive set and 0.55 for the exclusive set). Sensitivities of the ICD-9-CM codes for complications were 0.34 for the inclusive set and 0.14 for the exclusive set. Corresponding positive predictive values were 0.32 and 0.37, respectively. Sensitivities of code definitions for individual complications were generally poor, less than 0.5 in most cases.

CONCLUSIONS

The authors conclude that ICD-9-CM codes in discharge abstracts are poor measures of complication occurrence.