Data management

Explanation

Plans to handle the data collected from trial participants helps to promote data validity and integrity. A Data Management Plan details how the data will be collected, processed, secured, stored, and shared during and after a trial. Guidance is available on the content of Data Management Plans.(401-403)

Differences in data entry methods can affect the trial in terms of data accuracy, cost, and efficiency. For example, when compared with paper case report forms, electronic data capture can reduce the time required for data entry, and allow for efficient data validation, query resolution, and database release by combining data entry with data collection (Item 25a).(386, 404) When data are collected on paper forms, data entry can be performed locally or at a central site. Local data entry can enable fast correction of missing or inaccurate data, while central data entry facilitates blinding (masking), standardisation, and training of a core group of data entry personnel.

Raw, non-numeric data are usually coded for ease of data storage, review, tabulation, and analysis. It is important to define standard coding practices to reduce errors and observer variation. When data entry and coding are performed by different individuals, it is particularly important that the personnel use unambiguous, standardised terminology and abbreviations to avoid misinterpretation.

Standard processes are often implemented to improve the accuracy of data entry and coding.(391, 405) Common examples include double data entry;(406) verification that the data are in the proper format (e.g., integer) or within an expected range of values; and independent source document verification of a random subset of data to identify missing or apparently erroneous values (Item 29). Though performed to detect data entry errors, the time and costs of independent double data entry from paper forms need to be weighed against the magnitude of reduction in error rates compared with single data entry.

For trials in which both trail participants and personal are blinded, it is important to plan the timing and procedures for unblinding the trial (e.g., after the creation of a cleaned and locked data file).

Among two samples of trial protocols approved in 2016, 64% to 75% reported the data entry and coding processes.(9, 10) The protocol should fully describe the plans for data entry and processing, along with measures to promote their quality, or outline key elements with a reference to the Data Management Plan where full information can be found. These details are particularly important for the primary outcome data. The protocol should also document data security measures to prevent unauthorised access to or loss of participant data, as well as plans for data storage (including time frame) during and after the trial. This information facilitates an assessment of adherence to applicable standards and regulations.

Summary of key elements to address

● Processes for data management, including:

o Data entry and coding, including measures to reduce errors (e.g., double data entry, range checks for data values):

o Data security

o Data storage, including time frame

● Reference to where full information can be found (e.g., Data Management Plan), if not in the protocol