Original Article
Acute admissions to medical departments in Denmark: Diagnoses and patient characteristics

https://doi.org/10.1016/j.ejim.2014.06.017Get rights and content

Highlights

  • Non-specific diagnoses are prevalent in patients with chronic diseases.

  • Overlap between the patients' chronic diseases and reason for admission was found.

  • Age, gender and chronic diseases varied considerably according to main reason.

Abstract

Background

Despite extensive research on individual diseases, population-based knowledge about reasons for acute medical admissions remains limited. Our aim was to examine primary diagnoses, Charlson Comorbidity Index (CCI) score, age, and gender among patients admitted acutely to medical departments in Denmark.

Methods

In this population-based observational study, 264,265 acute medical patients admitted during 2010 were identified in the Danish National Registry of Patients (DNRP), covering all hospitals in Denmark. Reasons for acute admissions were assessed by primary diagnoses, grouped according to the International Classification of Diseases 10th edition. Additionally, the CCI score, age and gender were presented according to each diagnostic group.

Results

Two-thirds of the patients had one of the four following reasons for admission: cardiovascular diseases (19.3%), non-specific Z-diagnoses (“Factors influencing health status and contact with health services”) (16.9%), infectious diseases (15.5%), and non-specific R-diagnoses (“Symptoms and abnormal findings, not elsewhere classified”) (11.8%). In total, 45% of the patients had a CCI score of one or more and there was a considerable overlap between the patients' chronic diseases and the reason for admission. The median age of the study population was 64 years (IQR 47–77 years), ranging from 46 years (IQR 27–66) for injury and poisoning to 74 years (IQR 60–83) for hematological diseases. Gender representation varied considerably within the diagnostic groups, for example with male predominance in mental disorders (59.0%) and female predominance in diseases of the musculoskeletal system (57.8%).

Conclusion

Our study identifies that acute medical patients often present with non-specific symptoms or complications related to their chronic diseases.

Introduction

Acute medical patients comprise a high proportion of hospitalized patients, and they often present with complex problems and multiple chronic conditions [1], [2]. Despite extensive research on individual diseases, population-based knowledge about reasons for acute medical admissions remains limited [3], [4], [5].

Two European studies have reported that cardiovascular diseases are the leading causes for admissions to departments of internal medicine [3], [4]. However, both studies lacked detailed information on comorbidity, age, and gender according to diagnostic groups. The non-specific diagnoses from the Z-chapter of the International Classification of Diseases 10th edition (ICD-10) have been found to have a surprisingly high prevalence among acute admissions [6], [7], [8]. This reflects failure to classify the patients in specific diagnostic groups or failure to meet the patients' diagnostic or consultative needs.

Currently, services provided by inpatient medical departments face the challenge of demographic change. As the population ages, the prevalence of multiple chronic conditions is increasing [1], [9]. Knowledge about reasons for acute medical admissions and associated comorbidity levels, age, and gender is important both for physicians in departments of internal medicine and acute medical admission units and for healthcare planners.

We therefore conducted a population-based observational study of patients with acute admissions to inpatient medical departments in Denmark during 2010. We examined the primary diagnostic groups, Charlson Comorbidity Index (CCI) scores, age, and gender. In addition, we determined the source of admission, the length of hospital stay, and the distribution of individual conditions in the CCI, according to the primary diagnostic groups.

Section snippets

Study setting

We conducted this population-based observational study in Denmark using the Danish National Registry of Patients (DNRP), a national healthcare registry covering all hospitals [10]. Every Danish citizen is assigned a unique personal identification number at birth or immigration (CPR number), with embedded information on birth date and sex. These identifiers permit unambiguous individual-level linkage among all Danish population-based registries.

The Danish population (5,535,000 million people as

Gender and age

We identified 264,265 patients admitted acutely to the 178 medical departments in Denmark in 2010. While the overall study population included 51.3% females (Table 1), gender distribution varied among the diagnostic groups, for example with male predominance in mental disorders (59.0%) and cardiovascular diseases (55.3%), and female predominance in diseases of the musculoskeletal system and connective tissue disorders (57.8%) and hematological diseases (57.4%) (Table 2).

The median age of the

Key findings

In this population-based observational study, we found that two-thirds of the patients admitted acutely to the medical departments had one of the following four main reasons for admission: cardiovascular diseases, non-specific Z-diagnoses, infectious diseases, and non-specific R-diagnoses. The finding of high proportion of patients with non-specific diagnoses, particularly in patients with chronic diseases, is striking. In addition, we found considerable disparity in age, gender and chronic

Learning points

  • In this large nationwide study describing the main reasons for acute admission to medical departments we found a strikingly high proportion of patients with non-specific diagnoses, particularly in patients with chronic diseases.

  • Complications to chronic diseases are probably a common reason for admission, as we found a considerable overlap between the patients' chronic diseases and reason for admission.

  • There were a considerable disparity in age, gender and chronic disease distribution according

Financial support

The study was supported by the Clinical Epidemiological Research Foundation, Denmark, and the Aarhus University Research Foundation, Denmark.

Contributors

BV-H, AHR, HTS, and CFC contributed to the study conception, design, and the interpretation of data. BV-H, AHR, HTS, and CFC were responsible for the acquisition of data. BV-H analyzed and drafted the manuscript. All authors critically revised the manuscript and approved the final version.

Conflict of interest statement

We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.

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