Parent/carer email about postcodes

What precautions do you take to make sure an individual cannot be identified from their postcode?

There are general precautions about the security of our servers which I am sure every good business would adopt, but we make a special effort with postcodes.

I don't know if your child competed the survey online or on paper - the account to be given in each case is slightly different.

Online, the postcodes are encrypted using GnuPG when storing, and downloaded with the encryption intact (screenshot). 

Screenshot 2014-07-30 16.28.29.png

They are decrypted only when the postcode information is required; the decrypted postcode is not stored but discarded once the analysis is complete.

For paper surveys, we store only part of the postcode with the case, replacing the last two letters with "99", like this:

SCHID PUPILID SEX AGE YEAR PCODE Q1 Q2 etc
712 1 0 12 8 9999999 1 0
712 2 0 13 8 SG19399 0 1
712 3 1 13 8 SG19299 0 1
712 4 0 13 8 SG19399 0 0
712 5 0 13 8 SG19399 1 0
etc       

We store the whole postcodes separately from the rest of a pupil's answers as below, tagged with two numbers which together can identify an individual case, and merge the information only when necessary, and don't keep the merged data file.

SCHID PUPILID PCODE1 PCODE2
746 2 CB013 LN
746 3 CB013 LN
746 4 CB013 BN
746 5 CB014 ET
746 6 CB013 PU

In Cambridgeshire, we have used postcodes only for things like allocating pupils to districts - as a pupil may go to school in one district but live in another.  The reports produced are at the level of district rather than at the pupil level.

20% Cambridge City
16% East Cambs
22% Fenland
19% Huntingdonshire
19% South Cambs

Elsewhere, we have used postcodes for allocating deprivation scores, assigning ward-level information, and so on; again, we keep the derived information and discard the postcode. An example of an analysis using deprivation scores is given below:

Topics: 

Comments about SHEU

"You have made a truly significant contribution to health education and health promotion of young people in, not only England, but all over the United Kingdom and beyond." Colleague from NHS Scotland paying tribute to John Balding, presented at his retirement lunch, May 2005

NHS Scotland

"We're very happy to commission another survey from you. Our colleagues in School Improvement are dead keen to work with us on this. During our last LA Inspection, we were flagged from our Tellus data as having a bullying problem. We could demonstrate with our SHEU data - which had a much better sample size and coverage of the authority - that we did not have the problem they suggested. The Inspectors went away happy and we are definitely surveying again with SHEU."

Local Authority Senior Adviser

“(The SHEU survey) was very, very useful. It gave us reassurance we weren’t missing a trick. For example not many pupils in the sample year groups were taking illegal drugs, which re-enforced our opinions. But the survey also raised issues and flagged some things up. We discovered that some of our girls weren’t eating enough – the percentage of girls in our school not eating lunch the day before the survey was higher than the county average. There were other concerns too, specifically around cigarettes, alcohol and attendance.
The school used this data and took a number of actions to address it. More female peer mentors were put in place and the school asked NEXUS (the Extended Schools service) for help, so they developed a programme for girls which addressed their eating patterns, healthy eating, sex education and self-esteem issues.
We ran an anti-bullying group for Year 9 as a preventative measure, based upon data provided by our current Year 10 students.
The travel data revealed that a high number of pupils took the car to school so we involved the BIKE-IT scheme who ran assemblies, brought in their bikes (including one with a pedal-powered smoothie maker!), and raised awareness of health and green issues.
The information about how happy the students were with their lives raised some concerns as far fewer girls were as happy as the boys, so work was done around developing aspirations, role-models and self-esteem."        
 

Deputy Head, Secondary School

"Our use of the Health-Related Behaviour Questionnaire was commended as part of our accreditation for the National Healthy Schools Scheme." Headteacher

"Thanks for presenting the survey to local schools this morning, I just wanted to thank you for such interesting and thought-provoking information.  
I’m really glad we were able to take part - the information (particularly headline data and differences) will support us to have some really interesting questions with the Year group as a whole about the sense they’re making of this; what they think it might mean in terms of changes they might make, and what they need to support them in this."

Deputy Headteacher

...Many thanks for all your work with this year’s survey. It’s already proving to be invaluable especially against the severe cuts in services that are looming.

Health Promotion Manager

"The system works and I find quite a lot of it useful in my work. I've also recommended it to others."

Teenage Pregnancy Manager

"...the most comprehensive health education survey."

Daily Telegraph

"Just to say a huge thank you for all your efforts in helping us with the Health survey amongst pupils. It has provided us with significant data which will be used across the school to help us improve. It helped us to obtain a healthy schools standard as well. I hope we can make this an annual feature as we can track the changing health of our pupils." Headteacher

Headteacher

Thank you for following up with schools the comments that caused concern. It is very sad to hear that some of our children have these thoughts and feelings and I am so grateful that you were able to make the schools aware of this so that they can attempt to offer some support.

This is another reason why I am so pleased that we have been able to work with you to offer this survey.

Health and Wellbeing Adviser