Methodology

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Data source

The scope of the global database includes the 194 Member States in the six World Health Organization (WHO) regions: Africa (AFR), The Americas (AMR), Eastern Mediterranean (EMR), Europe (EUR), South-East Asia (SEAR) and Western Pacific (WPR).

A questionnaire is being used to collect information concerning organizational structures, legislative systems and activities related to organ donation and transplantation procedures. The questionnaire is annually distributed to the identified network of health authorities and officially designated individuals contributing to the global database.

Based on these data, with due consideration to potential biases, the Spanish Transplant Organization (ONT) working group and WHO have developed and currently maintain, a joint analysis dataset of national donation and transplantation estimates for countries, using a survey data since 2007. This survey was created by the group and improved in several occasions. After several years compiling data, some limitations were observed in the use of the survey/questionnaire. Therefore, WHO conducted a consultation process among Member States represented under the six WHO regions with the aim of improving it. The new questionnaire was piloted and finally agreed upon. This version is running since 2012 although the indicators per donor age were added lately in 2014.

The questionnaire covers three sections and the data are classified into two categories:

  • Qualitative data:

    • Organizational structures:  Yes/No responses
    • Legislative aspects: Yes/No responses
    • Both sections include open questions allowing free texts responses.

  • Quantitative data:

    • Donation (Actual and Utilized donors) and Transplantation activities (kidney, liver, heart, lung, pancreas, small bowel).

Other data sources

The United Nations Population Fund (UNFPA) report is used as the data source for estimates of population size. All charts and bar charts created with the GODT website application use the UNFPA data for all years and all countries. However, some statistics showed in the Reports prior to 2012 apply the most up-to-date figure available from an official source, instead of the UNFPA figure

Figures for Human Development Index (HDI) and other development indicators are obtained from the United Nations Development Programme (UNDP).

This is the Workflow for the annual collection of activity data:

Captura

As part of the revision process, personal communication, via e-mail or phone, is used to clarify any discrepancies with the data.

To solve the problem of dropout or missing data, for the annual reports and the trends analyses -progress of donation and transplantation activities-, we use the last observation carried-forward to avoid the loss of countries with no available data from the previous year. It is a common method used in clinical trials and longitudinal studies where individuals are followed. This method allows examining the trends over the time.

Calculation of estimates

National statistics are examined in both regional and global contexts. For the annual reports we use descriptive statistics with SPSS software. Data are presented in absolute numbers and rates per million population (pmp). Global and regional rates are calculated by applying the global and total regional population as the denominator.

We also apply inferential statistics to study the relation between some selected development indicators, such as the HDI.

The official maps are produced by the Public Health Information and Geographic Information System at WHO derived from a datasheet of the Global Database.

Acknowledgements

This work is being possible thanks to the collaboration with the network of health authorities and officially designated focal points.