By Verity Katuszka and Emma James

The Avon Longitudinal Study of Parents and Children (ALSPAC), affectionately known as Children of the 90s, is a large-scale population study which recruited over 14,000 pregnant women in 1991-92. It has followed up these families ever since and has accrued a wealth of health and lifestyle data collated from questionnaires, physical examinations, health records and biological sample analysis. The study is very proud to be celebrating its 21st anniversary this year and is very grateful for the continued support of the study families but, over the last 20 years, the number of actively engaged participants has reduced considerably. Response rates were particularly good in the first few years but the attrition rate reached its peak when the study children were 15-16 years old. To reduce the problem, ALSPAC has developed methods to encourage participation. 

In 2006, ALSPAC realised that to ensure participants would continue taking part in the study we needed to involve them in the research planning. We recruited members of the young cohort to join an advisory panel, known as TAP. In the past six years TAP members have been asked to advise on study documentation, data collection proposals and study design; members sit on the study’s ethics committee and frequently share their opinions about the future of ALSPAC. 

TAP Members at work

Whilst best practice might suggest that individuals involved in the research planning should not become participants in the same research, we feel that for longitudinal cohorts, and certainly for ALSPAC, our study participants are absolutely best placed for involvement in our research planning. As we have been a part of our participants’ lives for more than 20 years some of them have become expert research participants. It is not appropriate for us to consult the general public because they cannot know what it is like to be an ALSPAC participant and therefore cannot tell us what is acceptable to our participants, where participation turns into burden or how best to engage with a cohort of people we have been following for 21 years. As ALSPAC is an epidemiological study our participants are also not under our care. So whilst some of our participants may be patients or service users outside of the study, it would not be appropriate or necessary for us to involve patient groups in our research planning. The fact that six years on TAP is still playing a very important part within ALSPAC is evidence of its achievement and success. 

TAP member Emma says: “From the participant perspective it is great that we get a unique opportunity to see the whole research process. In a recent example TAP members, including myself, were asked to advise on proposed study documentation, we spoke to the scientists wanting to conduct the research and highlighted logistical issues that they had not considered. We advised them that participants would feel more comfortable, in this particular situation, if they hired a female member of staff to complete the data collection and gave our opinions around the subject of reimbursement for participants’ time. Some months later I have also had the opportunity, as an ALSPAC participant, to take part in this particular piece of research. It is really reassuring for me to know that the researchers take our opinions and ideas into consideration and great that I get an opportunity to see this happening first hand. I feel like I’m helping to improve the study for other ALSPAC participants by being part of TAP, which will hopefully encourage my peers to continue to take part in the study for years to come.”

ALSPAC’s experience demonstrates that when developing methods to involve participants of a longitudinal study, neither ‘public’ nor ‘patient’ accurately describes their research relationship. Therefore, we believe that another ‘P’ is necessary when it comes to PPI (public and patient involvement in research).  

ALSPAC participants


Contact: Verity Katuszka, Participation Worker, ALSPAC, University of Bristol or Emma James, TAP Member and ALSPAC Participant

Email: or

Tel: 0117 3313393 (Verity Katuszka)