although the danish health care system is tax - funded and provides free health care for all residents , there are variations in services offered across regions and hospitals in denmark.1 therefore , the danish regions decided in 2013 to establish a national quality database for unplanned health care contacts in hospitals in denmark.2,3 the danish clinical registers thus established the danish database for acute and emergency hospital contacts ( ddaehc ) based on principles from former national indicator databases .
the aim of ddaehc is to monitor the quality of care for all unplanned hospital contacts in denmark and thereby provide data on the evolution of acute health care .
the database covers all unplanned contacts at any somatic hospital in denmark from january 1 , 2013 and provided the first public report in 2016 covering 2013 till the first half of 2015 with an expected number of 1.7 million reported acute contacts per year.5 ddaehc includes any visit to a somatic emergency department as well as any somatic in - hospital ward regardless of presenting complaint and department designation ( eg , internal medicine , surgery , pediatrics ) .
data are gathered from the danish national patient registry ( dnpr ) , which includes all admissions to danish hospitals since 1977 and outpatient clinic visits and emergency department visits since 1995.6 the dnpr include individual contacts , that is , if a patient is transferred between departments and/or hospitals , this will count as two or more individual contacts .
the new ddaehc merges all such related contacts into a single contact ( or admission ) including all individual contacts from the time of first contact to the time of discharge from latest contact in the same admission .
thus , if the patient is transferred to another department or hospital within 3 hours , these will be included within the specific admission and count as one admission ( figure 1 ) .
the ddaehc includes ten quality indicators  two outcome indicators and eight process indicators ( table 1 ) .
the first result indicator is short - term mortality within 7 days after hospital arrival and includes both inpatient and outpatient deaths , if they occur within this 7-day period .
the smr is based on a risk adjustment model inspired by a uk model for 7-day mortality.8 the model was developed by a logistic regression analysis of 7-day mortality including age , sex , comorbidity ( inpatient or outpatient diagnosis within each of the 19 conditions in the charlson comorbidity index within 5 years prior to the current contact ) , and main diagnosis from current hospital contact .
the smr is computed as the observed mortality in the unit of interest divided by the expected mortality computed as the sum of each patient s estimated mortality using the prediction model .
the second result indicator is readmission within 72 hours after leaving hospital for patients with a combined index stay of < 24 hours duration .
planned returns are not included if coded appropriately as a nonacute contact . using patient tracers of different clinical time - dependent conditions ,
four process indicators describe time from arrival until diagnosis or treatment for respectively stroke , st - elevation myocardial infarction , suspected or confirmed perforated hollow viscera , and wrist fracture .
selected indicators from some of the disease - specific quality databases are used to supplement the broad overview of quality in the danish acute and emergency system .
time to thrombolysis in patients with ischemic stroke is included from the danish stroke register , while the other three are computed using time of treatment reported to the dnpr . from the danish database for emergency surgery ,
the ddaehc includes a fifth process indicator describing the proportion of circulatory unstable patients presenting with suspected or confirmed upper gastrointestinal peptic ulcer bleeding stabilized within 60 minutes after arrival . finally , three process indicators present data on patients admitted through emergency admission units .
these include time to triage , time to first physician contact , and time to assessment by a specialist physician .
besides variables used for computing quality indicators , the database includes several variables for case - mix consideration and adjustment , for example , age , sex , charlson comorbidity index conditions , civil status , residency , and discharge diagnoses ( table 2).9 ddaehc also includes the identity of the initial department with responsibility for the patient treatment during the admission ; but at present , individual emergency departments and admission units can not reliably be identified as other departments in some cases are responsible for the treatment .
if there is no registration in dnpr , it is assumed that the patient did not have a diagnosis or procedure of interest .
it is therefore not possible to distinguish absence of a condition / procedure from missing values .
while dnpr and data from the stroke register is considered a reliable source,6,1012 comparison with other external data sources are required to estimate the validity of some of the data .
therefore , there is an ongoing validation of the recorded time of x - ray in the dnpr compared with hospital registration and initiatives have been initiated in order to validate recorded time of percutaneous coronary intervention in dnpr as neither has been previously used in registries such as this .
currently , validity of the used time registrations as well as registration of planned return visits in the dnpr is unknown .
besides variables used for computing quality indicators , the database includes several variables for case - mix consideration and adjustment , for example , age , sex , charlson comorbidity index conditions , civil status , residency , and discharge diagnoses ( table 2).9 ddaehc also includes the identity of the initial department with responsibility for the patient treatment during the admission ; but at present , individual emergency departments and admission units can not reliably be identified as other departments in some cases are responsible for the treatment .
if there is no registration in dnpr , it is assumed that the patient did not have a diagnosis or procedure of interest .
it is therefore not possible to distinguish absence of a condition / procedure from missing values .
while dnpr and data from the stroke register is considered a reliable source,6,1012 comparison with other external data sources are required to estimate the validity of some of the data .
therefore , there is an ongoing validation of the recorded time of x - ray in the dnpr compared with hospital registration and initiatives have been initiated in order to validate recorded time of percutaneous coronary intervention in dnpr as neither has been previously used in registries such as this .
currently , validity of the used time registrations as well as registration of planned return visits in the dnpr is unknown .
as ddaehc is based on data from dnpr and the danish civil registration system,6,7 it is continuously updated .
patients are followed for procedures performed , readmissions , and death within 7 days after arrival .
the first official report covering all acute hospital contacts from 2013 till june 30 , 2015 has been released in the beginning of 2016.5 the quality indicators as provided by ddaehc are primarily to be used to follow local performance ( provided case - mix remains unchanged ) . as residual confounders
inevitably will be present in the very diverse populations of acute patients that attend different departments , data provided by ddaehc can not be used to benchmark between regions , hospitals , and departments . however , the major strength of ddaehc is complete coverage of all unscheduled hospital visits combined with demographic and disease - specific variables .
this provides the possibility for a global overview of the quantity , flow , and distribution of all acute hospital contacts in denmark .
the database provides numerous possibilities for descriptive studies of demographic characteristics of the acute hospital contacts in regions with different prehospital and in - hospital services
furthermore , the database can be used to assess change in quality related to organizational modifications13 as well as significance of time of contact ( eg , day vs night and weekday vs weekend ) in the acute population and for specific patient categories . for chosen patient tracers ( identified by international classification of diseases , 10th
revision , diagnosis in the dnpr6 ) , the database can describe regional differences in organization of the acute setting for specific patients with the possibility to relate to outcome described in the database as well as other outcome defined in the studies .
the ddaehc is funded by the danish regions and receive administrative , epidemiological , and biostatical support from the danish clinical registries , danish regions .
aggregated data will be reported annually in a published report , and individual - level data are provided monthly to relevant clinicians and hospital managers through each region s information system .
the ddaehc is a new database established by the danish regions including all acute hospital contacts in denmark .
the database includes specific outcome and process health care quality indicators as well as demographic and other basic information with the purpose to be used for enhancement of quality of acute care .
 aim for databaseaim of the danish database for acute and emergency hospital contacts ( ddaehc ) is to monitor the quality of care for all unplanned hospital contacts in denmark ( acute and emergency contacts).study populationthe ddaehc is a nationwide registry that completely covers all acute and emergency somatic hospital visits at individual level regardless of presentation site , presenting complaint , and department designation since january 1 , 2013.main variablesthe ddaehc includes ten quality indicators  of which two are outcome indicators and eight are process indicators . 
 variables used to compute these indicators include among others day and time of hospital contact , vital status , st - elevation myocardial infarction diagnosis , date and time of relevant procedure ( percutaneous coronary intervention , coronary angiography , x - ray of wrist , and gastrointestinal surgery ) as well as time for triage and physician judgment . 
 data are currently gathered from the danish national patient registry , two existing databases ( danish stroke register and danish database for emergency surgery ) , and will eventually include data from the local and regional clinical logistic systems.descriptive datathe ddaehc also includes age , sex , charlson comorbidity index conditions , civil status , residency , and discharge diagnoses . 
 the ddaehc expects to include 1.7 million acute and emergency contacts per year.conclusionthe ddaehc is a new database established by the danish regions including all acute and emergency hospital contacts in denmark . 
 the database includes specific outcome and process health care quality indicators as well as demographic and other basic information with the purpose to be used for enhancement of quality of acute care . 
Background
Aim of the database
Study population
Main variables
Descriptive variables
Missing data and validity
Follow-up
Examples of research
Administrative issues and funding
Conclusion