Linking records: what factors affect consent in a longitudinal study? ShareThis


Many of CLOSER’s partner studies’ participants are asked for their permission to link their data with other datasets. But what factors make members give consent to their data being linked?

To help answer this question, Tarek Al Baghal, Research Fellow at the Institute for Social and Economic Research wrote the article: Obtaining data linkage consent for children: factors influencing outcomes and potential biases which featured in the International Journal of Social Research Methodology (2015).

Tarek comments, “This research is the first to explore consent rates for children in a large national survey and seeks to understand who consents (or not) and possible reasons why. Identifying the ‘who’ and ‘why’ are important steps in knowing of possible data quality issues.”

Two samples were used from the first wave of Understanding Society, a large General population sample (GP) plus the Ethnic Minority Boost which is an additional sample of 6,000 adults from ethnic minority backgrounds.

The researchers found that mothers consent at higher rates for themselves than for their child and nearly 60% of mothers said yes to both health and education records, 29.2% said no to both, and 11.4% said yes to one and no to the other. They also discovered that consent for health records is lower than for education records.

What demographics affect consent? 

The research revealed that those owning their home have lower predicted odds of consent for either children’s health or education records, as is having a university degree. Other measures such as employment status and household income show no significant impact. The researchers also found that those supporting left-leaning political parties are more likely to consent to linkage of children’s administrative records, as are those expressing a greater tendency to trusting strangers. Interestingly, the proportion of children consented for is smaller in London and the South East England.

For both consent requests, minority ethnicities generally have lower predicted odds than British or Irish whites. Tarek comments on why this finding could affect the representativeness of the sample,

“The significant differences in consent across ethnicities raise other concerns when the data in the linked record are correlated with these demographics. For example, certain health conditions are more prevalent in certain ethnic populations, and the prevalence of these conditions may be under-represented if these populations consent at lower rates.”

What can be done to improve the level of consent?

“Given that mothers who are harder-to-contact (and possibly more resistant to taking the survey) are more likely to refuse consent requests, it may be fruitful to improve strategies for reducing survey resistance and increasing willingness to participate.”

“Longer interviews lead to higher consent rates, so building a rapport with the respondent may lead to higher consent rates. This can be achieved through interviewer training and developed by the interviewer while interacting with the respondent,” says Tarek.

How is permission granted for data linkage?

During their interview, respondents are told their study would like to link records to their survey responses. They are given a leaflet which explains the details. This request is immediately followed by a consent form to link their records, which they are asked to sign.


Related links


Further information

Obtaining data linkage consent for children: factors influencing outcomes and potential biases by Tarek Al Baghal, International Journal of Social Research Methodology (2015).

How consistent is respondent behaviour to allow linkage to health administrative data over time?” by Tarek Mostafa and Richard D Wiggins, is the latest working paper to be published by the UCL IOE’s Centre for Longitudinal Studies.