Methodology and Quality Update

Latest Update on Methodology and Quality

29/04/2026

Statistical Presentation

Data description

Health and Safety at Work Statistics present data on health and safety at work, defining the objective of the statistical data and the phenomenon they address, namely, measuring and monitoring work-related risks, occupational diseases, and the extent to which a safe and healthy work environment is available in Saudi Arabia.
It is a statistical product conducted to collect data on the main characteristics as follows:
•    Accidents and injuries at work.
•    Work-related health problems.
•    Workplace risks.
•    Healthcare for workers.
Data is also used to estimates:
•    The percentage of individuals exposed to chemicals.
•    The percentage of individuals exposed to heavy metals.
•    The percentage of individuals who reported a work-related accident during the past 12 months.
•    Work-related health problems and accidental injuries.
•    The percentage of employees (aged 18 years and above) who are exposed to risks at work.
•    The relative distribution of occupational injuries among employees (aged 18 years and above).
•    The relative distribution of work-related health problems during the past 12 months among employees (aged 18 years and above).
•    The percentage of employees (18 years and older) who received medical care or treatment for work-related injuries or health issues.
•    The percentage of employees (aged 18 years and above) by basic health coverage, sex, and nationality.
•    The percentage of employees (aged 18 years and above) who received training on occupational health and safety procedures.
•    The percentage of employees (aged 18 years and above) whose employer provides a dedicated occupational health and safety unit.
•    The percentage of employees (aged 18 years and above) who undergo regular medical check-ups at the workplace.

Classifications

The following classifications are applied in the health and safety at work statistics publication:
The National Classification for Economic Activities (ISIC4):
It is a statistical classification based on the International Standard Industrial Classification of All Economic Activities (ISIC4), used to describe the productive activities of an establishment.
Saudi Standard Classification of Occupations(ISCO_08):
It is a statistical classification based on the International Standard Classification of Occupations (ISCO-08), providing a system for classifying and grouping occupational information obtained from population censuses, statistical surveys, and administrative records.
This classification is used in the health and safety at work statistics to classify employees based on their occupations.
Saudi Classification of Specializations and Educational Levels (SASCED-20):
A statistical classification based on the International Standard Classification of Education (ISCED_11) and (ISCED_13) for education and training, issued by the United Nations Educational, Scientific, and Cultural Organization (UNESCO). It serves as the reference classification for organizing educational programs and qualifications according to their levels and fields of study. It comprehensively covers all educational programs, levels, and methods, spanning from early childhood education to higher education levels.
This classification is used in the Health and Safety at Work Statistics to classify individuals (aged 18 years and above) according to their fields of study and educational levels.
National Code of Countries and Nationalities (3166 ISO – codes Country):
A statistical classification based on the international standard  (ISO 3166_Country codes), which is a standard issued by the International Organization for Standardization (ISO of the UN), and this classification gives numeric and literal codes for the world’s (248) countries, based on the classification of countries. 
The classification is used in the Health and Safety at Work Statistics to classify individuals into Saudi and non-Saudi (country codes).
Metadata is collected through interviews so that outputs can be produced in accordance with all relevant classifications.
The classifications are available on the GASTAT’s website www.stats.gov.sa

Statistical concepts and definitions

Terms and concepts for health and safety at work statistics publication include:
•    Accidents and injuries at work:
Any unexpected event occurring in the workplace that results in injury or illness to an employee.
•    Work-related health problems:
Any illness or health condition resulting from exposure to hazardous factors in the workplace. These factors may be physical (such as noise, vibration, and radiation), chemical (such as toxic substances), biological (such as viruses and bacteria), or psychological stressors.
•    Workplace risks:
Any factor or condition in the workplace may lead to injury or illness to an employee. These risks may be obvious, such as the presence of sharp machinery, or hidden, such as continuous psychological stress.
•    Employee healthcare:
A set of services and activities aimed at maintaining the health and safety of workers in the workplace. These services include regular medical check-ups, health education, providing a safe work environment, managing health conditions, and offering first aid.

Data sources

Health and Safety at Work Statistics rely on two data sources:
First source: Data from the National Health Survey conducted by GASTAT.
The key variables of the survey data are as follows:
•    Sex.
•    Nationality.
•    Administrative region.
•    Age groups.
Second source: Administrative records for Health and Safety at Work Statistics from the National Council for Occupational Safety and Health.
The main published variables from the administrative data source are:
•    Economic activity.
•    Type of injury.

Designing the data collection tool

Data were collected using a questionnaire prepared and designed by specialists at GASTAT. The data collection instrument was designed in an electronic format (CAPI) to ensure ease of use by field researchers. International recommendations, standards, and definitions were taken into account in its design. The questionnaire was also reviewed by relevant stakeholders to obtain their views and feedback. Furthermore, the questions were formulated clearly and scientifically to standardize the wording and guidance of the questions. 
Sections of the questionnaire:
•    Demographic data.
•    Health Status.
•    Access to care, consultations, and unmet needs.
•    Nutrition and physical activity.
•    Smoking
•    Family planning.
•    Mental health.
•    Disability.
•    Health and safety at work.
Review and validation rules:
Audit and control rules have been established in the form to ensure that the data collected is consistent, accurate, and logical. These rules were developed by linking the logical relationships between answers, questions, and various variables to assist the field researcher in detecting any errors directly during data entry.
To ensure the quality of Health and Safety at Work Statistics data, three types of review and validation rules have been established, as follows:
•    Navigation rules between sections and fields:
Special rules were programmed to regulate automatic navigation between sections and fields based on the respondent’s answers, totaling 91 rules.
•    Error rules:
These are rules that cannot be bypassed during the data entry process. The field researcher must correct the data by referring back to the respondent to verify its accuracy. The total number of these rules exceeds 215.
•    Warning rules:
These rules are designed to verify the correctness of the data entered by the researcher. The field researcher may override them if the data accuracy is confirmed, with a total of approximately 18 rules.
Administrative data are collected based on standardized data request tables directed to data-owning entities to obtain periodic, harmonized, and documented data derived from administrative records related to health indicators, thereby ensuring improved data quality and integration across different data sources.

Questionnaire test (cognitive test)

Cognitive testing was conducted on a number of questionnaire items. The interview sample consisted of a random sample of households distributed across the regions of the Kingdom of Saudi Arabia. During the cognitive testing process, the following evaluation aspects were taken into account: (including the overall concept of the question, clarity of question wording, clarity of the terms used in the question, and the appropriateness of response options, in addition to assessing the participant’s ability to answer the questions effectively and their willingness to disclose responses), leading to the preparation of a report providing a comprehensive summary of the cognitive testing results.
Cognitive testing was conducted on several questionnaire items based on the cognitive testing pillars. Several observations were identified related to the following aspects (wording, comprehension, response options, and technical terms). Accordingly, the final questionnaire was redesigned.

Statistical population

The statistical population of Health and Safety at Work Statistics consists of employed individuals, both Saudi and non-Saudi, aged 18 years and above, who usually reside in Saudi Arabia. 

Sample Design

The sample for the National Health Survey 2025 was designed based on the 2022 Census frame, ensuring accurate representation of the statistical population across Saudi Arabia, including all administrative regions, age groups, sex, and nationality. A stratified cluster random sampling method was used, where enumeration areas were considered as primary sampling units, and households within the selected enumeration areas were considered as final sampling units.
Stratification:
To increase the efficiency of the sample and its representativeness of the target population, the primary sampling units in the sample frame were classified into homogeneous strata to obtain more accurate results compared to a simple random sample of the same size. The stratification was carried out as follows:
Sample size and allocation across strata:
The sample size was estimated at the level of administrative regions (study domains). The sample was then allocated across strata using proportional allocation to improve the precision of estimates by reducing the design effect through minimizing weight variance.
The total sample size amounted to 48,375 households. The sample size was calculated using the following parameters and determinants:  The estimates derived from the sample have a specified level of precision and coefficient of variation (CV). The acceptable CV used in calculating the sample size was less than 1% at the national level, 2% at the administrative region level, and 6.4% at the governorate level. The design effect used was 5.44. The response rate reached 80%. A confidence level of (1−α) = 0.95 was used in estimating the proportion. Sample distribution by administrative region.
Table of sample distribution at the level of administrative regions:

Statistical unit

The statistical unit in Health and Safety at Work Statistics is the individual.

Data collection

Data collection from the survey:
Data for Health and Safety at Work Statistics are collected through Computer-Assisted Personal Interviewing (CAPI), as follows:
•    National Health Survey:
A sample consisting of male and female individuals (Saudi and non-Saudi) aged 15 years and above. 
Data collection from administrative records:
Administrative data for Health and Safety at Work Statistics are obtained from the National Council for Occupational Safety and Health, in coordination with the relevant departments at GASTAT, and include data on occupational injuries.
The data are stored in GASTAT’s databases after undergoing verification and review processes in accordance with approved statistical methods and recognized quality standards. The data source is consulted in cases of detected errors or observations. Administrative data are also examined by checking consistency, ensuring completeness and logical coherence, and verifying the absence of duplication.

Data collection frequency 

The data collection process for Health and Safety at Work Statistics is conducted on an annual basis.

Reference area

Health and Safety at Work Statistics cover 13 administrative regions in Saudi Arabia and 151 governorates affiliated with these regions.

Reference period (time reference)

Reference period of the variables or dataset is as follows:
The data are referenced to the start date of data collection (06/07/2025).

Base period

Not applicable, as the Tourism Establishments Statistics publication provides data and indicators periodically to measure changes over time and is not compared to a fixed base period. 

Measurement unit

All results are calculated as percentages (such as the percentage of individuals exposed to chemicals).

Time coverage

Data are available from the year 2023 to 2025.

Publication frequency

Results of Health and Safety at Work Statistics are published on an annual basis in accordance with the approved statistical calendar.

Statistical processing

Error detection

Meticulous processes were implemented to detect errors in the collected data using automated and manual methods aimed at ensuring quality and accuracy. These included the following:
•    Identification of illogical or out-of-range values (such as impossible ages or contradictory data).
•    Detecting missing or incomplete data and handling it according to established policies.
•    Reviewing the internal consistency of the questionnaire responses to ensure data compatibility.
•    Data are reviewed and matched to ensure their accuracy and precision in a way that suits their nature, with the aim of giving the presented statistics quality and accuracy.
•    Data are processed and tabulated to ensure their accuracy prior to analysis.
•    All the outputs are stored and uploaded to the database after being calculated by GASTAT to be reviewed and processed by specialists in the Health and Education Statistics Department through modern technologies and software designed for this purpose.

Data integration and matching from multiple sources 

Data from multiple sources are integrated and matched using two main sources to produce Health and Safety at Work Statistics, to achieve data integration and enhance their accuracy and comprehensiveness. This is done by utilizing administrative records from the National Council for Occupational Safety and Health and linking them with statistical data produced by GASTAT. These data are processed in an integrated manner to ensure the completeness and accuracy of statistical outputs.
In the National Health Survey, the national ID of the head of the household is collected and linked to data from the National Information Center during the household interview. This is used to complete data on name, sex, date of birth, age, and relationship to the head of the household, which contributes to improving the quality of household demographic data. 

Imputation and calibration

Handling missing values (Imputation): 
•    Donor record method:
It is a statistical method used to impute missing values in records by replacing a missing value in a given record with a value from another similar record within the same sample.
•    Implementation steps:
-    Identifying the records that contain missing values.
-    Identifying similar donor records based on common characteristics such as: Age, sex, nationality, and administrative region.
-    Selecting the donor record either randomly or according to the closest match in characteristics.
-    Copying the required value from the donor record to the target record to compensate for the missing value.
Procedures for calculating variables:
Percentage of individuals by type of injury  ​​​​​= 

Where represents injuries resulting from exposure to chemicals, exposure to heavy metals, or a work-related accident.

Seasonal adjustments

Not applicable, only final results will be published. 

Adjustment of preliminary results 

Not applicable, only final results will be published.

Used Resources

Quality dimensions

Suitability

A criterion that measures the extent to which the product meets users’ needs.

User needs

Internal users at GASTAT of Health and Safety at Work Statistics data:
•    Social statistics
-    Population, gender, and diversity
-    Living conditions, lifestyles, and justice statistics
-    Health and education statistics.
Several external users and beneficiaries benefit from the data of the statistical product, including:
•    Government entities.
•    Regional and international organizations.
•    Research institutions.
•    Media.
•    Individuals.
Key variables utilized by external users:

Completeness 

Data for Health and Safety at Work Statistics are based on two sources:
•    Survey data from the National Health Survey.
•    Administrative data from the National Council for Occupational Safety and Health.
This is to provide comprehensive information on Health and Safety at Work Statistics, ensuring that the data are complete.

Accuracy and reliability 

A measure of the extent to which estimates or calculations are close to the actual values that reflect reality.

Overall accuracy 

•    Data quality is enhanced through the selection of researchers based on a set of practical and objective criteria related to the nature of the work, as well as their qualification and training.
•    Alert, prevention, and correction rules are applied during the data collection process on the electronic questionnaire for health and safety at work statistics to improve data quality.
•    The data is examined against previous years to identify any significant changes.
•    The internal consistency of the data is checked before it is finalized.
•    The links between variables are checked and coherence between different data series is confirmed.

Timeliness and punctuality 

Timeliness: A standard that indicates the length of time between the availability of information and the occurrence of the event.
Punctuality: It reflects the time lag between the data publication date and the target date when publication actually occurs.

Timeliness 

GASTAT is committed to applying internationally recognized standards regarding the announcement, clarification of the time of publishing statistics on its official website, as outlined in the statistical calendar, as well as adhering to the announced time of publication. In the event of any delay, updates will be provided accordingly.

Punctuality 

Publication is carried out in accordance with the release dates in the statistical calendar for Health and Safety at Work Statistics published on GASTAT’s website.
The data are available at the expected time, as scheduled in the statistical release calendar, If the publication is delayed, reasons shall be provided.

Coherence and comparability

A standard that refers to the necessity of internal and temporal consistency of statistics, their logical coherence, and their comparability and integration across different regions and sources.

Comparability - geographical

Statistical data related to Health and Safety at Work Statistics are fully comparable geographically within Saudi Arabia, as well as at the regional and international levels.

Comparability - over time 

Health and Safety at Work Statistics started in 2023 as an annual publication and are comparable over time.

Coherence- Cross domain

The data are consistent, as their coherence is verified against all other statistics containing similar indicators. These procedures contribute to ensuring integration and coherence among statistics, thereby enhancing data reliability and the quality of the analyses based on them, and ensuring that the results are free from any unjustified inconsistencies.

Coherence- Sub-annual and annual statistics 

Not applicable, as Health and Safety at Work Statistics are published on an annual basis and no sub-annual publications are issued.

Coherence- National Accounts 

Not applicable, as Health and Safety at Work Statistics are not linked to the national accounts, as they target households.

Coherence- Internal 

Estimates of Health and Safety at Work Statistics are fully internally consistent, as they are all based on the same set of microdata and are calculated using the same estimation methods.

Accessibility and clarity

It refers to users’ access to data, the availability of detailed and aggregate data, as well as the availability of the Methodology and Quality Report.

Press releases

The announcements for each publication are available on the statistical calendar as mentioned in 10.1. The press releases can be viewed on the website of GASTAT on the link: 
Press release

Publications

GASTAT issues the health and safety at work statistics on a regular basis within a pre-prepared dissemination plan which is published on GASTAT’s website. GASTAT is keen to publish its publications in a way that serves all users of different types, including publications in different formats that contain (publication tables, data graphs, indicators, metadata, methodology, and questionnaires) in both English and Arabic.
Results of the Health and Safety at Work Statistics are available on:
Health and Safety at Work Statistics

Online database

The data is published on the statistical database:
GASTAT (stats.gov.sa)

Microdata accessibility

Accurate data is unit-level disaggregated data obtained from multiple sources such as sample statistical surveys, general population and housing censuses, and administrative systems, providing detailed information about the characteristics of individuals, families, business entities, and geographical areas, supporting the construction and development of statistical indicators and scientific research.
Different types of microdata files are available to meet diverse information needs.
•    Public use: 
It consists of sets of records containing information on individuals, households, or business entities anonymized in such a way that the respondent cannot be identified either directly, such as by name, address, contact number, identity number, etc., or indirectly (by combining different – especially rare – characteristics of respondents), such as age, occupation, education, etc.
•    Scientific use:
These files are created in accordance with specific methodologies upon request by data users to extract datasets with defined characteristics for use in strategic studies, decision-making, and scientific research by individuals, households, and companies, while ensuring that they contain no direct identifiers and are subject to confidentiality protection controls.
Qualified users who meet the standards and procedures of confidentiality protection can access the files of scientific use of accurate data through the platform "ITAHA" of the General Authority for Statistics, while the most sensitive data for use is shared by visiting the accurate data laboratory within a secure environment managed by the Authority.

References and standards

Framework of the health and safety at work statistics.
GASTAT relied on formulas based on international standards to calculate the indicators The main indicators for Health and Safety at Work Statistics are as follows:
•    The (Eurostat) methodology was used to calculate indicators of work-related health problems and accidental injuries. 
•    The (SDGs) methodology was applied to calculate indicators related to occupational injuries.

Quality assurance

GASTAT ensures that the following principles are taken into account: Impartiality; ensuring that the statistical product is user-oriented; quality of processes and outputs; effectiveness of statistical operations; and reduction of the burden on respondents. 
Data is validated through procedures and quality controls that are applied during the process at various stages, such as data entry, data collection, and other final controls.

Quality assessment

GASTAT carries out all statistical activities in accordance with the National Model (Generic Statistical Business Process Model – GSBPM). During the comprehensive evaluation stage, which is the final stage of GSBPM, information collected across all stages and sub-processes is used to prepare an evaluation report that summarizes all challenges related to the quality of each statistical process and serves as an input for improvement and development processes.

Confidentiality

Confidentiality - Policy

According to Royal Decree No. 23 dated 07/12/1379, data must always be kept confidential and must be used by GASTAT for statistical purposes only.
Therefore, the data is protected in the data servers of GASTAT.

Confidentiality - Data Treatment

Data of SMEs survey are presented in right tables in order to summarize, understand, as well as extract their results. Moreover, to compare them with other data, and to obtain statistical significance about the selected study population. However, referring to such data indicated in tables is much easier than going back to check the original questionnaire that may include some data like names and addresses of individuals, and names of data providers, which violates data confidentiality of statistical data.
“Anonymity of data” is one of the most important procedures. To keep data confidential, GASTAT removed information on individual persons, households, or business entities in such a way that the respondent cannot be identified either directly, such as by name, address, contact number, identity number, etc., or indirectly by combining different, especially rare, characteristics of respondents, such as age, occupation, education, etc.

Dissemination policy

Statistical calendar

Health and Safety at Work Statistics have been included in the statistical calendar.
Statistical Calendar

User access

One of GASTAT’s objectives is to better meet its clients’ needs; therefore, it provides them with the results of Health and Safety at Work Statistics immediately upon their release.
Customer questions and inquiries regarding the publication and its results are also received through various communication channels, such as:
•    GASTAT official website:   www.stats.gov.sa
•    GASTAT official email address:  info@stats.gov.sa
•    Official visits to GASTAT’s official head office in Riyadh or one of its branches in Saudi Arabia.
•    Official letters.
•    Statistical telephone: (199009).