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Hospital Morbidity Survey

• 1Contact
  • 1.1Contact organisation
    National Statistics Institute of Spain
    
  • 1.5Contact mail address

    Avenida de Manoteras 50-52 - 28050 Madrid

    
    
• 2Metadata update
  • 2.1Metadata last certified
    12/03/2024
  • 2.2Metadata last posted
    27/04/2022
  • 2.3Metadata last update
    12/03/2024
• 3Statistical presentation
  • 3.1Data description

    The objectives of the Hospital Morbidity Survey (HMS) are:

    1. To know the general morbidity rate in hospitals based on the main diagnosis associated with hospital discharge.
    2. To determine the average stay in hospital.
    3. To serve as a base for epidemiological studies on specific diagnoses.
    4. To know the geographic distribution of morbidity.
    5. To provide a database of information that is standardised for all hospitals in the country, both public and private.
    6. To serve as a base for comparative national and international studies.

    Traditionally, information is collected through the use of two basic health documents such as the the Hospital Register and the Patient Record. Over the last few years, the concept of the Specialised Care Registry (SCR-MBDS) has been developed, which is an evolution of the current Minimum Basic Data Set on hospital discharges (MBDS), that represents a set of obtainable variables at the time of the patient's discharge and that respond to the needs of multiple users. This survey's concepts and definitions are obtained from this set of data.

    The objective variables are the number of hospital discharges and the length of the stay in hospitals.

    The classification variables used are the main diagnosis, the type of hospital admission, the reason for discharge and the province where hospitalisation occurred. With regards to patients, information on age, sex and place of residence is collected.

  • 3.2Classification system
    • Clasificaciones utilizadas

      Since 2016, the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) has been used to codify the main diagnosis that was behind admission into hospital (link: https://eciemaps.mscbs.gob.es/ecieMaps/browser/index_10_mc.html).

      
      
      

      Until 2015, the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) was used (link: https://eciemaps.mscbs.gob.es/ecieMaps/browser/index_9_mc.html ).

  • 3.3Sector coverage

    It covers all hospital discharges at all hospitals within the national territory, whether these are public (dependent on some kind of Administration, including the Ministry of Defence) or private (both charitable and for profit/non-profit).

  • 3.4Statistical concepts and definitions
    • Hospital discharge
      Discharge is defined as the procedure whereby a patient admitted to a Health Centre or Establishment no longer occupies a hospital bed, as a result of healing, recovery, death, transfer or self-discharge.
    • Basic Minimum Set of Data upon the hospital discha
      This represents a set of variables obtainable at the time of the hospital discharge of the patient, and which meet the needs of many users.
    • Diagnóstico Principal
      Es la afección que después del estudio necesario se establece que fue causa del ingreso en el hospital de acuerdo con el criterio del servicio clínico o facultativo que atendió al enfermo, aunque durante su estancia hayan aparecido complicaciones importantes e incluso otras afecciones independientes.
    • Hospital stay
      The stay is defined as the discharge date minus the admission date, not computing stays equal to zero
    • Patient
      Every person who has gone to a hospital centre to be seen, diagnosed or observed in an in-patient regime, and which has led to a hospital admittance.
  • 3.5Statistical unit

    The survey's statistical unit is the discharge of a patient or sick person who has stayed in a health centre for at least one night. To obtain this information, the different centres established on the national territory are contacted; these are the respondent units.

  • 3.6Statistical population

    The survey's target population are sick people in hospitals that have stayed for at least one night.

  • 3.7Reference area

    The geographical scope is the whole of the national territory including Ceuta and Melilla.

    The level of disaggregation is to the province level in some of the tables published.

  • 3.8Time coverage

    The survey is carried out annually and data are collected on all the discharges that have taken place within the reference year, regardless of when the patient was admitted and what the reason for discharge was.

  • 3.9Base period

    The Hospital Morbidity Survey is a statistical investigation that began in 1977.

• 4Unit of measure
  • 4.1Unit of measure

    Number of people discharged from hospitals.

• 5Reference period
  • 5.1Reference period

    The requested data refer to the calendar year covered by the survey.

    Data referred to the period: Anual A: 2022

• 6Institutional mandate
  • 6.1Legal acts and other agreements

    The compilation and dissemination of the data are governed by the Statistical Law No. 12/1989 "Public Statistical Function" of May 9, 1989, and Law No. 4/1990 of June 29 on “National Budget of State for the year 1990" amended by Law No. 13/1996 "Fiscal, administrative and social measures" of December 30, 1996, makes compulsory all statistics included in the National Statistics Plan. The National Statistical Plan 2009-2012 was approved by the Royal Decree 1663/2008. It contains the statistics that must be developed in the four year period by the State General Administration's services or any other entity dependent on it. All statistics included in the National Statistics Plan are statistics for state purposes and are obligatory. The National Statistics Plan 2021-2024, approved by Royal Decree 1110/2020, of 15  December, is the Plan currently implemented. This statistical operation has governmental purposes, and it is included in the National Statistics Plan 2021-2024. (Statistics of the State Administration).

    
    

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  • 6.2Data sharing
    The exchanges of information needed to elaborate statistics between the INE and the rest of the State statistical offices (Ministerial Departments, independent bodies and administrative bodies depending on the State General Administration), or between these offices and the Autonomic statistical offices, are regulated in the LFEP (Law of the Public Statistic Function). This law also regulates the mechanisms of statistical coordination, and concludes cooperation agreements between the different offices when necessary.
    

    A collaboration agreement exists with Cataluña through which the Community sends the required information on the hospitals within its territorial scope.

    INE collaborates with the Andalucia, Aragon and Castilla La Mancha, on the basis of which these Communities send the information on the hospitals in their jurisdiction. Through the Ministry of Defence, information is collected on the hospitals that are dependent on this institution.

    A signed agreement exists with EUSTAT (Basque Statistics Office) on the basis of which they provide all the information on hospitals in their Community.

    For its part, INE sends the anonymised registries to the various Communities once the results are published.

• 7Confidentiality
  • 7.1Confidentiality - policy

    The Statistical Law No. 12/1989 specifies that the INE cannot publish, or make otherwise available, individual data or statistics that would enable the identification of data for any individual person or entity. Regulation (EC) No 223/2009 on European statistics stipulates the need to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and the access to those confidential data with due account for technical developments and the requirements of users in a democratic society

    
    
  • 7.2Confidentiality - data treatment
    INE provides information on the protection of confidentiality at all stages of the statistical process: INE questionnaires for the operations in the national statistical plan include a legal clause protecting data under statistical confidentiality. Notices prior to data collection announcing a statistical operation notify respondents that data are subject to statistical confidentiality at all stages. For data processing, INE employees have available the INE data protection handbook, which specifies the steps that should be taken at each stage of processing to ensure reporting units' individual data are protected. The microdata files provided to users are anonymised.
    

    The confidentiality of the data collected when the patient is discharged from hospital, both by the MBDS system and by means of the Hospital Register, is guaranteed as it is established in the respective regulations that the competent authorities may only access this data for statistical or study purposes, maintaining in all cases the confidential nature of the information recorded and the anonymity of the persons concerned.

• 8Release policy
  • 8.1Release calendar

    The advance release calendar that shows the precise release dates for the coming year is disseminated in the last quarter of each year.

    
    
  • 8.2Release calendar access

    The calendar is disseminated on the INEs Internet website (Publications Calendar)

    
    
  • 8.3User access

    The data are released simultaneously according to the advance release calendar to all interested parties by issuing the press release. At the same time, the data are posted on the INE's Internet website (www.ine.es/en) almost immediately after the press release is issued. Also some predefined tailor-made requests are sent to registered users. Some users could receive partial information under embargo as it is publicly described in the European Statistics Code of Practice

    
    
• 9Frequency of dissemination
  • 9.1Frequency of dissemination

    Annual

• 10Accessibility and clarity
  • 10.1News release

    The results of the statistical operations are normally disseminated by using press releases that can be accessed via both the corresponding menu and the Press Releases Section in the web

    
    
  • 10.2Publications

    The results of the survey are released through the INE webpage and some of the results are covered in publications such as the Anuario Estadistico (Statistical Yearbook), Cifras INE (INE Figures), etc.

    The information published includes:

    - the Survey's Press Release.

    - Detailed results of the last year published and previous years.

    - Connection between the published diagnoses and the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) . Since HMS 2016

    - Correspondence between the published diagnoses and the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) . Until HMS 2015.

    - Correspondence between the reduced international Eurostat/OECD/WHO list and the WHO's International Classification of Diseases (9th Review CM). Until HMS2015

  • 10.3On-line database

    INEbase is the system the INE uses to store statistical information on the Internet. It contains all the information the INE produces in electronic formats. The primary organisation of the information follows the theme-based classification of the Inventory of Statistical Operations of the State General Administration . The basic unit of INEbase is the statistical operation, defined as the set of activities that lead to obtaining statistical results on a determined sector or subject based on the individually collected data. Also included in the scope of this definition are synthesis preparation.

    
    

    Information on the last publication of the HMS can be accessed from the INEbase in the health section and at the following link:

    https://www.ine.es/dyngs/INEbase/en/operacion.htm?c=Estadistica_C&cid=1254736176778&menu=ultiDatos&idp=1254735573175

  • 10.4Micro-data access
    A lot of statistical operations disseminate public domain anonymized files, available free of charge for downloading in the INE website Microdata Section
    

    Microdata from this statistic can be accessed inder specific conditions. These files are anonymised so that the hospital from which information comes cannot be identified nor, in any case, can the person who was discharged, as the data that would enable this are not collected.

  • 10.5Other

    As well as the microdata, the valid variable values and correspondences with the International Classification of Diseases (ICD) can be found on the same page as the microdata file.

    Interested users can request, through the INE Information Area (at https://www.ine.es/ss/Satellite?c=Page&p=1254735638180&pagename=ProductosYServicios%2FPYSLayout&cid=1254735638180&L=1 ), specific, tailored use of information that is carried out whilst preserving data confidentiality in all cases.

  • 10.6Documentation on methodology

    Methodology:

    For a detailed description of the methodology, a direct link is attached.

    https://www.ine.es/en/daco/daco42/sanitarias/notaemh16_en.pdf

    Questionnaire:

    The information is mainly collected through the exchange of files with hospitals or Health Services in a predefined format. The design of the record of the published microdata file can be found at (ftp://www.ine.es/temas/morbihos/disreg_morbi_en.zip).

    However, a small number of hospitals still exist that require visiting and information to be collected directly from the Hospital Register via a questionnaire. For this, staff are available as a base for the collection of data in a uniform manner, thus facilitating the uploading of data onto the application.

  • 10.7Quality documentation

    This standardised methodological report contains all the elements of what is considered a "user-oriented quality report", for this operation.

• 11Quality management
  • 11.1Quality assurance

    Quality assurance framework for the INE statistics is based on the ESSCoP, the European Statistics Code of Practice made by EUROSTAT. The ESSCoP is made up of 16 principles, gathered in three areas: Institutional Environment, Processes and Products. Each principle is associated with some indicators which make possible to measure it. In order to evaluate quality, EUROSTAT provides different tools: the indicators mentioned above, Self-assessment based on the DESAP model, peer review, user satisfaction surveys and other proceedings for evaluation.

    
    

    INE's territorial units (Provincial Delegations) are involved in the collection of information, which allows for closer proximity to the respondent units (hospitals), which, in turn, guarantees improved information coverage control. Furthermore, there is collaboration with various bodies of the administration that are responsible for the management of hospitals (Autonomous Community councils, Ministry of Defence, Penal Institutions) with the aim of obtaining information directly through these bodies and therefore reducing the burden on respondents.

    To guarantee the quality of information, validation and variable inconsistency controls are established for all records (valid variables, codification of diagnoses according to the International Classification of Diseases (ICD-9-CM until 2015, ICD-10-CM Spanish edition from 2016). In the event that the file exceeds a minimum number of errors, the respondent unit is contacted to correct the detected issues.

    Once the information is validated, a filtering phase is carried out and data is imputed using the DIA programme (system for filtering and automatic imputation of qualitative data that follows the Fellegi-Holt methodology and has been developed by INE). In its design, deterministic rules are used that allow systematic and random errors to be dealt with in a single process. Each field is modified once at the most, avoiding unnecessary imputations and leaving the records consistent.

  • 11.2Quality assessment

    Thanks to the computerisation of the hospital records and to the existence by law of a Minimum Basic Data Set for all the hospitals, this survey's coverage is nearly exhaustive. Currently, over 96% of hospitals and 97% of discharges throughout Spain are covered. In some Communities these figures are close to 100% (the number of discharges is near 4.7 million).

    Furthermore, the sending of information from hospitals through files allows for the application of quality criteria on data when obtaining information, rejecting those that have a significant non-response rate on the main target variable (at least 90% of the diagnoses should be specified). Equally, strict validation controls and controls on coherence between variables are applied.

    For these reasons, the data's precision and reliability is fairly high. The improvements in the centralised data processing procedure aims to reduce the publication times.

    The application of the International Classification of Diseases guarantees international coherence and comparability of the survey's information.

• 12Relevance
  • 12.1User needs

    The survey's users include:

    - Autonomous Communities

    - Businesses (Public and Private)

    - Researchers and Universities.

    Each of these users have different needs regarding the destination and utility of the information they require. In many cases, specific information is requested on some of the ICD codes corresponding to diseases that are being researched to study their impact on the population. Sometimes, although the information can be found in the published microdata, a quote is requested for a specific use of data including data from previous years.

  • 12.2User satisfaction

    The INE has carried out general user satisfaction surveys in 2007, 2010, 2013,  2016 and 2019 and it plans to continue doing so every three years. The purpose of these surveys is to find out what users think about the quality of the information of the INE statistics and the extent to which their needs of information are covered. In addition, additional surveys are carried out in order to acknowledge better other fields such as dissemination of the information, quality of some publications...

    On the INE website, in its section Methods and Projects / Quality and Code of Practice / INE quality management / User surveys are available surveys conducted to date.(Click  next link)

     

    
    

    The specific needs of users are considered whenever methodological reviews of the survey are carried out, in order to adapt the content of the survey to their specific requirements, thus increasing their satisfaction levels.

  • 12.3Completeness

    The HMS satisfies all the requirements established in national and international regulations related to the survey, in this way allowing it to comply with all requests it receives.

    Indicator R1=100%

• 13Accuracy and reliability
  • 13.1Overall accuracy

    The survey's accuracy is very high due to the near-exhaustiveness of the survey. 97% of total hospital discharges are covered (and 96% of hospitals).

    The possible errors are due to a partial non-response in the main diagnoses of the discharge (main target variable), although due to coverage and validation controls in the receipt of the files, this is minimal (0.2% of the total collected).

     

  • 13.2Sampling error

    The investigation is exhaustive, there are no sampling errors.

  • 13.3Non-sampling error

    The framework of respondent units is the National Hospital Catalogue (hospitals with inpatient care).

    The percentage of hospitals that have not been covered (non-response from respondent units) is 4% of the total hospitals.

    (Indicator A4=4%)

    The partial non-response in the diagnosis (main target variable) is 0.3% of the 4.7 million records.

    (Indicator A5=0.3%)

• 14Timeliness and punctuality
  • 14.1Timeliness

    T2: The data corresponding to the year 2022 have been published within a period of 15 months (TP=15). 

    The time frames continued to be reduced in previous years thanks to an increase in the use of new technologies in the various hospital centres, which has allowed information to be provided in a more efficient and structured manner, thus facilitating the later filtering stage as well as the integration of the information with the rest of the collected information.

    In the first years of the survey's existence, it was published two years after the reference date, mainly due to the use of paper in the collection of information and to its previous manual recording, which increased the length of the filtering and imputation periods.

  • 14.2Punctuality

    Data is released in accordance with the structural statistics availability calendar prepared and published by INE for each year, without any delays in the past few years.

• 15Coherence and Comparability
  • 15.1Comparability - geographical

    The same criteria in the definition of the variables and the use of the International Classification of Diseases (ICD-10-CM) mean that the HMS is comparable with other European Union countries that publish this information. A common collection, filtering, editing and elevation process throughout the national geographic scope guarantees the comparability of results between different Autonomous Communities and Cities and between provinces.

  • 15.2Comparability - over time

    The International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) was used for the first time in 2016, which marks an important change with respect to previous years. Comparison with other years is not always guaranteed as there is no unequivocal relationship between the classifications used. However, considering the large groups of diseases, it is possible to make comparisons with other years. (Indicator CC2 = 45 years)

    The International Classification of Diseases (9th Review) has been applied since 1980, although the clinically modified version has been used since 2010. Until 2004, it was codified to 3 digits and, between 2005 and 2015, it was codified to 4 digits.

  • 15.3Coherence - cross domain

    It is possible to establish a certain relationship with Ministry of Health statistics shown below but with different nuances:

    - Statistics on Health Care Institutions with Inpatient Facilities (ESCRI): From all hospitals, the total number of discharges that each one has recorded is collected, as well as other variables.

    - Specialised Care Registry. SCR-MBDS: It is an evolution of the Minimum Basic Data Set on hospital discharges, created for the analysis of caseloads in hospitalisation. The hospitals' discharges are recorded with records designed based on the MBDS, however, they do not encompass all private and psychiatric hospitals, and medium- and long-stay hospitals.

  • 15.4Coherence - internal

    The information is coherent and all variables have been maintained over time.

• 16Cost and burden
  • 16.1Cost and burden

    The respondent unit is the hospital. As, in the majority of computerised cases, hospital information is provided through the Specialised Care Registry (SCR-MBDS) guaranteed by the National Health System, there is no excessive cost to the hospital for providing the information. Where the SCR-MBDS is not available, different possible types of record designs are provided so that the hospital can provide the file. These formats have a undergone change with respect to previous years due to the use of the new classification and, in some cases, they represented additional work in 2016, however, once implemented, in successive years they did not pose an overload of work.

    The estimated budgetary appropriation needed to finance this statistic, as provided for in the 2024 Annual Programme is 191.59 thousand Euros.

• 17Data revision
  • 17.1Data revision - policy

    The INE of Spain has a policy which regulates the basic aspects of statistical data revision, seeking to ensure process transparency and product quality. This policy is laid out in the document approved by the INE board of directors on 13 March of 2015, which is available on the INE website, in the section "Methods and projects/Quality and Code of Practice/INE’s Quality management/INE’s Revision policy" (link).

    This general policy sets the criteria that the different type of revisions should follow:  routine revision- it is the case of statistics whose production process includes regular revisions-; more extensive revision- when methodological or basic reference source changes take place-; and exceptional revision- for instance, when an error appears in a published statistic-.

    
    

    There is no review of published data.

  • 17.2Data revision - practice

    Not applicable.

• 18Statistical processing
  • 18.1Source data

    - The Ministry of Health publishes the National Hospital Catalogue annually. The INE uses it to establish a population framework that will be the subject of the investigation.

    - From each hospital, information is collected on all patients who have stayed for at least one night. If the hospital is computerised, it sends INE the data that it has, following the established design. In those hospitals where the data are not computerised, data should be collected manually from the Hospital Register.

  • 18.2Frequency of data collection

    Collection from hospitals is carried out according to the availability of each hospital. In the majority of cases, hospitals provide data annually, although some hospitals send their data every six months, every four months or quarterly.

  • 18.3Data collection

    INE, through its Provincial Delegations, contacts the hospitals in each of the provinces. If the data are computerised, the files with the requested information are sent directly and are then processed. Where data are not computerised, it is needed preparing a file with data that is then loaded into the relevant application so that this data is processed with the rest of the information collected.

  • 18.4Data validation

    Prior to the validation of microdata, a list of hospitals from which definitive information has been received is prepared, indicating the number of records that the associated file should theoretically have.

    When the information received from hospitals is loaded, the programme initially validates that the records are in the correct format, detecting any invalid values. When the data are transferred, the coherence of the information is validated, which, according to the codification of the Classification of Diseases, cannot include invalid values and must ensure that the data provided reach the minimum level of quality required.

    Sometimes, hospitals only send disease records, meaning the INE must codify all those records that are not complete. Later, there are automated and manual filtering and imputation processes that review incompatibilities and inconsistencies between the data.

  • 18.5Data compilation

    Once all the information provided by the various hospitals is grouped in a single file, the following checks are carried out (previously, the format was validated and invalid values were corrected):

    - Duplicated records are identified: total duplicates are deleted and partial duplicates are analysed to discuss what to do in each case.

    - A preliminary list of notices regarding the possible warnings in ICD and EDAD correspondence is applied and possible inconsistencies are corrected.

    - Informative lists on the collected sample, the quality of the codification of the ICD and its validity are obtained.

    - The procedure for filtering and automatic imputation of data is carried out.

    The elevation factors are calculated considering the number of records collected and the purposes of the hospitals.

    - The tables and microdata are reviewed prior to their release.

  • 18.6Adjustment

    No adjustments are carried out.

• 19Comment
  • 19.1Comment