Hospital Morbidity Survey (HMS) 1951-2011

Summary

The Hospital Morbidity Survey (HMS) was initially implemented in 1951 and since then, it has been elaborated annually. It aims at obtaining the structure and development of hospital morbidity, that of the ill persons who were admitted into hospitals, by measuring the different diagnoses, average stay in hospital by type of diagnosis and the hospital’s area of influence. Strengths: The survey provides information availability on a national level, policy about the hospital resources, international statistical standards, homogeneous information between the different hospitals and administrations, and confidentiality of patient discharge data remains guaranteed.

Type of data

Data Source
Registry + Survey

Type of Study
Crosssection regular

Data gathering method
Face-to-face
Registries
Other: Most data from registries are taken electronically.

Access to data

Conditions of access
On site free access to defined tables and microdata files for scientific purpose and elaboration. Notes for general use and for media are available in English. - Free access to Spanish general tables: http://www.ine.es/jaxi/menu.do?type=pcaxis&file=pcaxis&path=%2Ft15%2Fp414%2F%2Fa2011&L=0 - General microdata files and microdata files divided by diagnosis groups (since 1996) are available in Spanish and English (1978-2011): http://www.ine.es/prodyser/micro_morbihos.htm

Type of available data (e.g. anonymised microdata, aggregated tables, etc.)
Aggregated and elaborated tables, as well as anonymised microdata.

Formats available
Microdata: ASCII zip file following a register design file (EXCEL format) Tables: PC-Axis, Excel and CSV

Coverage

Coverage Years of collection, reference years, and sample sizes
Data collection is ongoing since 1978.

First year of collection
1951, although data are homogenised from 1978 onwards

Stratification if applicable
Stratified by region and type of hospital (general, surgical, maternal…)

Base used for sampling

Geographical coverage and breakdowns
All of Spain, regions and provinces

Age range
Patients of all ages discharged from hospitals

Statistical representativeness
Population representative

Coverage of main and cross-cutting topics
The main objective consists of obtaining the structure and development of hospital morbidity, in other words, of the ill persons who were admitted into hospitals. Specifically, it tries to measure morbidity by virtue of the different diagnoses, average stay in the hospital by type of diagnosis, and the hospitals’ scope of influence or degree of attraction. The fulfilment of the Survey's objectives was guaranteed with the introduction of the obligatory use of basic health documents in 1977: the Patient Register and the Patient File, which granted the systematic recording of all patients who were admitted to and discharged from hospital. In the last few years, a new hospital information system has been developed for patient discharge, known as the Basic Minimum Set of Data (BMSD), which responds to the needs of multiple users (management, planning, epidemiological research, statistical purposes, etc.) and which includes a number of administrative and clinical data collected when the patient is discharged. This system makes homogenous information between different hospitals available and covers the Survey objectives to the same extent that the Patient Register did in the past.

Linkage

Standardisation
HMS follows the diagnoses classified according to the WHO International Classification of Diseases ICD-9-CM, as well as the reduced Eurostat/OECD/WHO list.

Possibility of linkage among databases
This data source is linked to some administrative health registers such as the Basic Minimum Set of Data (BMSD) for hospital admissions for general purpose in connection with the International statistical standards. It is also standardized with other administrative documents to share information (BMHDS, for both public and private hospitals, and the Record Book, mainly for those centres that lack computerised monitoring of patients). Nevertheless, records in the database of statistics are anonymous and cannot be identified for subsequent crosses.

Data quality

Entry errors if applicable
Some technological and organizational changes have led to removing some variables (civil status, motives for access) in the collection process over time due to the lack of response. Information about the type of hospital (public vs private) has been added recently in accordance to the transfer of health assistance from the central government to regional administration. The majority of hospitals have mechanised information available on recorded discharges. For those hospitals that do not have mechanised information available, the information is collected via a printed questionnaire by filling it with the data taken from the official Patients Register.

Breaks
HMS introduced two basic health documents, the Patient Register and the Patient Record, which systematically recorded all patients who were admitted and discharged from the hospital. The Basic minimum set of hospital admissions data relating to the patient (BMSD) was developed and implemented in 1987 to obtain the essential variables related to the patients’ admission to the public and private hospitals. This instrument fulfils the need of having a hospital information system adapted to the autonomous and functional dimensions of the National Health System and of being comparable with other EU countries.

Consistency of terminology or coding used during collection
The use of official standardized documents (registries) makes the data collection very consistent with international regulations and the data analysis comparable in international settings. Changes in Classification of Diseases are incorporated to HMS as they have been internationally approved.

Governance

Contact information
Social Statistics and Analyses Directorate
Instituto Nacional de Estadística (Spanish Statistical Office, INE)
Castellana 183
28071 Madrid Spain Phone: 91 583 91 00
Email: infoine(at)ine.es
Url: http://www.ine.es/jaxi/menu.do?type=pcaxis&path=/t15/p414&file=inebase&L=0

Timeliness, transparency
Tables are published within the year following the survey.