Readmission and mortality in patients discharged with a diagnosis of medical observation and evaluation (Z03*-codes) from an acute admission unit in Denmark: a prospective cohort study

Acute patients discharged without an established diagnosis: risk of mortality and readmission of nonspecific diagnoses compared to disease-specific diagnoses

BACKGROUND

Nonspecific discharge diagnoses after acute hospital courses represent patients discharged without an established cause of their complaints. These patients should have a low risk of adverse outcomes as serious conditions should have been ruled out. We aimed to investigate the mortality and readmissions following nonspecific discharge diagnoses compared to disease-specific diagnoses and assessed different nonspecific subgroups.

METHODS

Register-based cohort study including hospital courses beginning in emergency departments across 3 regions of Denmark during March 2019-February 2020. We identified nonspecific diagnoses from the R- and Z03-chapter in the ICD-10 classification and excluded injuries, among others-remaining diagnoses were considered disease-specific. Outcomes were 30-day mortality and readmission, the groups were compared by Cox regression hazard ratios (HR), unadjusted and adjusted for socioeconomics, comorbidity, administrative information and laboratory results. We stratified into short (3-<12 h) or lengthier (12-168 h) hospital courses.

RESULTS

We included 192,185 hospital courses where nonspecific discharge diagnoses accounted for 50.7% of short and 25.9% of lengthier discharges. The cumulative risk of mortality for nonspecific vs. disease-specific discharge diagnoses was 0.6% (0.6-0.7%) vs. 0.8% (0.7-0.9%) after short and 1.6% (1.5-1.7%) vs. 2.6% (2.5-2.7%) after lengthier courses with adjusted HRs of 0.97 (0.83-1.13) and 0.94 (0.85-1.05), respectively. The cumulative risk of readmission for nonspecific vs. disease-specific discharge diagnoses was 7.3% (7.1-7.5%) vs. 8.4% (8.2-8.6%) after short and 11.1% (10.8-11.5%) vs. 13.7% (13.4-13.9%) after lengthier courses with adjusted HRs of 0.94 (0.90-0.98) and 0.95 (0.91-0.99), respectively. We identified 50 clinical subgroups of nonspecific diagnoses, of which Abdominal pain (n = 12,462; 17.1%) and Chest pain (n = 9,599; 13.1%) were the most frequent. The subgroups described differences in characteristics with mean age 41.9 to 80.8 years and mean length of stay 7.1 to 59.5 h, and outcomes with < 0.2-8.1% risk of 30-day mortality and 3.5-22.6% risk of 30-day readmission.

CONCLUSIONS

In unadjusted analyses, nonspecific diagnoses had a lower risk of mortality and readmission than disease-specific diagnoses but had a similar risk after adjustments. We identified 509 clinical subgroups of nonspecific diagnoses with vastly different characteristics and prognosis.

Critically deviating vital signs among patients with non-specific diagnoses-A register-based historic cohort study

BACKGROUND

One third of ambulance patients receive non-specific diagnoses in hospital. Mortality is 3-4%, however due to the high patient volume this group accounts for 20% of all deaths at day 30. Non-specific diagnoses do not provide much information on causes for death. Vital signs at first contact with ambulance personnel can act as a proxy for the patient's condition. Thus, we aimed to describe the prevalence of abnormal vital signs, as determined by a modified NEWS2, in ambulance patients who received a non-specific hospital diagnosis. Secondly, we examined the association between vital signs, NEWS2 scores, type of non-specific diagnosis, and mortality among these patients.

METHODS

Register-based historic cohort study of ambulance patients aged 16+ in the North Denmark Region during 2012-2016, who received a non-specific diagnosis (ICD-10 chapters R or Z) at hospital. We used NEWS2 scores to determine if first vital signs were normal or deviating (including critical). Mortality was estimated with the Kaplan-Meier estimator. Association between vital signs and mortality was evaluated by logistic regression.

RESULTS

We included 41,539 patients, 20.9% (N = 8,691) had normal vital signs, 16.3% (N = 6,766) had incomplete vital sign registration, 62.8% (N = 26,082) had deviating vital signs, and of these 6.8% (N = 1,779) were critical. If vital signs were incompletely registered or deviating, mortality was higher compared to normal vital signs. Patients with critical vital signs displayed the highest crude 48-hour and 30-day mortality (7.0% (5.9-8.3) and 13.4% (11.9-15.1)). Adjusting for age, sex, and comorbidity did not change that pattern. Across all vital sign groups, despite severity, the most frequent diagnosis assigned was Z039 observation for suspected disease or condition unspecified.

CONCLUSIONS

Most ambulance patients with non-specific diagnoses had normal or non-critical deviating vital signs and low mortality. Around 4% had critical vital signs and high mortality, not explained by age or comorbidity.

Importance of Reporting Complete Procedures of Identifying Patients from the Danish National Patient Registry: The Case of Neonatal Jaundice and Epilepsy

Objective

The Danish National Patient Registry (DNPR) is a valuable resource for medical and epidemiological Research. However, not all research articles fully described procedures they used to identify events. In this study, we compared two approaches in identifying persons with a disease diagnosis using neonatal jaundice and epilepsy as examples.

Methods

A cohort of singletons born alive between the 1st January 1997 and the 30th November 2016 in Denmark was used for this purpose. Diagnostic information for a hospital contact in the registry included a primary diagnosis, secondary diagnoses, referral diagnoses, and additional information to a diagnosis (associated diagnoses), if any. Approach 1 identified patients of interest by considering all diagnostic information with exclusion of referral diagnoses only. Approach 2 identified patients of interest by additionally excluding diagnoses from a hospital contact that were coded with Z00 – Z99 of ICD-10 (for health service on examination and reproduction, etc.) as the main reason of the hospital contact. We presented the proportion of people with a diagnosis of neonatal jaundice and epilepsy by the two approaches and explored the potential explanations for the difference.

Results

For the example of neonatal jaundice, the study population included N=1,186,683 persons. The proportion of children with a diagnosis of neonatal jaundice was 5.5% (n=66,736) by approach 1 and 3.9% (n=45,928) by approach 2. For the example of epilepsy, the study population included N=1,183,273 persons. The proportion of children with a diagnosis of epilepsy were 1.2% (n=14,604) by approach 1 and 0.9% (n=10,441) by approach 2.

Discussion

This study demonstrated that the two approaches identified different proportion of persons with a diagnosis of neonatal jaundice and epilepsy. We advocated researchers report complete procedures of identifying patients for making research findings reproducible and comparable.

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Profiling Bispebjerg Acute Cohort: Database Formation, Acute Contact Characteristics of a Metropolitan Hospital, and Comparisons to Urban and Rural Hospitals in Denmark

Purpose

To present a metropolitan cohort, Bispebjerg acute cohort (BAC), and compare patient characteristics and outcomes with patients from urban and rural hospitals in Denmark.

Patients and Methods

We linked data from seven Danish nationwide registries and included all acute contacts to non-psychiatric hospitals in the years 2016–2018. Acute hospital contacts to Bispebjerg and Frederiksberg Hospital constituted BAC, representing a solely metropolitan/urban catchment area. Patient characteristics and outcomes were compared to the rest of Denmark in an urban cohort (UrC) and a rural cohort (RuC), stratified by visit and hospitalization contact types.

Results

We identified 4,063,420 acute hospital contacts in Denmark and BAC constituted 8.4% (n=343,200) of them. BAC had a higher proportion of visits (65.1%) compared with UrC (52.1%) and RuC (45.3%). Patients in BAC more often lived alone (visits: BAC: 34.8%, UrC: 30.6%, RuC: 29.2%; hospitalizations: BAC: 50.8%, UrC: 36.7%, RuC: 37.2%) and had temporary CPR number (visits: BAC: 4.4%, UrC: 1.9%, RuC: 1.6%; hospitalizations: BAC: 1.5%, UrC: 0.9%, RuC: 0.8%). Visit patients in BAC were younger (BAC: 36, UrC: 42, RuC: 45 years, median), more often students (BAC: 18.0%, UrC: 14.0%, RuC: 12.5%), and had more contacts due to infectious diseases (BAC: 19.8%, UrC: 14.1%, RuC: 6.2%) but less due to injuries (BAC: 40.0%, UrC: 43.8%, RuC: 60.7%). Hospitalized patients in BAC had higher median age (BAC: 64, UrC: 61, RuC: 64 years) and fewer were in employment than in UrC (BAC: 26.1%, UrC: 32.1%, RuC: 28.1%). BAC Hospitalizations had a lower death rate within 30 days than in RuC (BAC: 3.0% [2.9–3.1%], UrC: 3.1% [3.0–3.1%], RuC: 3.4% [3.3–3.4%]), but a higher readmission-rate (BAC: 20.5% [20.3–20.8%], UrC: 17.3% [17.2–17.4%], RuC: 17.5% [17.5–17.6%]).

Conclusion

Significant differences between BAC, urban, and rural cohorts may be explained by differences in healthcare structure and sociodemographics of the catchment areas.

Non-specific diagnoses are frequent in patients hospitalized after calling 112 and their mortality is high - a register-based Danish cohort study

Background

The number of patients calling for an ambulance increases. A considerable number of patients receive a non-specific diagnosis at discharge from the hospital, and this could imply less serious acute conditions, but the mortality has only scarcely been studied. The aim of this study was to examine the most frequent sub-diagnoses among patients with hospital non-specific diagnoses after calling 112 and their subsequent mortality.

Methods

A historical cohort study of patients brought to the hospital by ambulance after calling 112 in 2007–2014 and diagnosed with a non-specific diagnosis, chapter R or Z, in the International Classification of Diseases, 10th edition (ICD-10). 1-day and 30-day mortality was analyzed by survival analyses and compared by the log-rank test.

Results

We included 74,847 ambulance runs in 53,937 unique individuals. The most frequent diagnoses were ‘unspecified disease’ (Z039), constituting 47.0% (n 35,279). In children 0–9 years old, ‘febrile convulsions’ was the most frequent non-specific diagnosis used in 54.3% (n 1602). Overall, 1- and 30-day mortality was 2.2% (n 1205) and 6.0% (n 3258). The highest mortality was in the diagnostic group ‘suspected cardiovascular disease’ (Z035) and ‘unspecified disease’ (Z039) with 1-day mortality 2.6% (n 43) and 2.4% (n 589), and 30 day mortality of 6.32% (n 104) and 8.1% (n 1975).

Conclusion

Among patients calling an ambulance and discharged with non-specific diagnoses the 1- and 30-day mortality, despite modest mortality percentages lead to a high number of deaths.

Symptom, diagnosis and mortality among respiratory emergency medical service patients

OBJECTIVE

Breathing difficulties and respiratory diseases have been under-reported in Emergency Medical Services research, despite these conditions being prevalent with substantial mortality. Our aim was two-fold; 1) to investigate the diagnostic pattern and mortality among EMS patients to whom an ambulance was dispatched due to difficulty breathing, and 2) to investigate the initial symptoms and mortality for EMS patients diagnosed with respiratory diseases in hospital.

METHODS

Population-based historic cohort study in the North Denmark Region 2012-2015. We included two patient groups; 1) patients calling the emergency number with breathing difficulty as main symptom, and 2) patients diagnosed with respiratory diseases in hospital following an emergency call. Main outcome was estimated 1- and 30-day mortality rates.

RESULTS

There were 3803 patients with the symptom breathing difficulty, nearly half were diagnosed with respiratory diseases 47.3%, followed by circulatory diseases 13.4%, and symptoms and signs 12.0%. The 1-day mortality rate was highest for circulatory diseases, then respiratory diseases and other factors. Over-all 30-day mortality was 13.2%, and the highest rate was for circulatory diseases (17.7%) then respiratory diseases and other factors. A total of 4014 patients were diagnosed with respiratory diseases, 44.8% had the symptom breathing difficulty, 13.4% unclear problems and 11.3%. chest pain/heart disease. 1-day mortality rates were highest for decreased consciousness, then breathing difficulties and unclear problem. Over-all 30-day mortality rates were 12.5%, the highest with symptoms of decreased consciousness (19.1%), then unclear problem and breathing difficulty. There was an overlap of 1797 patients between the two groups.

CONCLUSIONS

The over-all mortality rates alongside the distribution of symptoms and diagnoses, suggest the breathing difficulty patient group is complex and has severe health problems. These findings may be able to raise awareness towards the patient group, and thereby increase focus on diagnostics and treatment to improve the patient outcome.

Diagnosis and mortality of emergency department patients in the North Denmark region

Background

Emergency departments handle a large proportion of acute patients. In 2007, it was recommended centralizing the Danish healthcare system and establishing emergency departments as the main common entrance for emergency patients. Since this reorganization, few studies describing the emergency patient population in this new setting have been carried out and none describing diagnoses and mortality. Hence, we aimed to investigate diagnoses and 1- and 30-day mortality of patients in the emergency departments in the North Denmark Region during 2014–2016.

Methods

Population-based historic cohort study in the North Denmark Region (580,000 inhabitants) of patients with contact to emergency departments during 2014–2016. The study included patients who were referred by general practitioners (daytime and out-of-hours), by emergency medical services or who were self-referred.

Primary diagnoses (ICD-10) were retrieved from the regional Patient Administrative System. For non-specific diagnoses (ICD-10 chapter ‘Symptoms and signs’ and ‘Other factors’), we searched the same hospital stay for a specific diagnosis and used this, if one was given. We performed descriptive analysis reporting distribution and frequency of diagnoses. Moreover, 1- and 30-day mortality rate estimates were performed using the Kaplan-Meier estimator.

Results

We included 290,590 patient contacts corresponding to 166 ED visits per 1000 inhabitants per year. The three most frequent ICD-10 chapters used were ‘Injuries and poisoning’ (38.3% n = 111,274), ‘Symptoms and signs’ (16.1% n = 46,852) and ‘Other factors’ (14.52% n = 42,195). Mortality at day 30 (95% confidence intervals) for these chapters were 0.86% (0.81–0.92), 3.95% (3.78–4.13) and 2.84% (2.69–3.00), respectively.

The highest 30-day mortality were within chapters ‘Neoplasms’ (14.22% (12.07–16.72)), ‘Endocrine diseases’ (8.95% (8.21–9.75)) and ‘Respiratory diseases’ (8.44% (8.02–8.88)).

Conclusions

Patients in contact with the emergency department receive a wide range of diagnoses within all chapters of ICD-10, and one third of the diagnoses given are non-specific. Within the non-specific chapters, we found a 30-day mortality, surpassing several of the more organ specific ICD-10 chapters.

Trial registration

Observational study - no trial registration was performed.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3361-x) contains supplementary material, which is available to authorized users.