Research Access

The NILS dataset is a sensitive dataset. Because of this, micro data files are not available to users. Instead, the NILS microdata can only be is accessed within a ´safe setting´.  The data access process is described below.

Step-by step guide to accessing NILS data

In this section we explain how to access the data within the step-by-step. These steps are required for all projects. However, some pilot work to test whether a particular research question is feasible may be possible and this can be discussed with the NILS Support Team. Although a number of steps are involved for most projects, we aim to make this a smooth operation with the minimum necessary time delays.

Step 1: Formulate your research question

You should explore the NILS website, and particularly the data dictionary, to see whether the research question you are interested in could be explored with the NILS. It might also be useful to investigate research that has been conducted using the E&WLS, and the SLS as many of these studies could be replicated using the NILS; a publications list for the E&WLS can be found by clicking on E&WLS Publications and for the SLS by clicking on SLS Publications.

If you are not sure whether the NILS is suitable for your research, please discuss it further with a member of the NILS support team.

Due to legislative restrictions all research must be related to the health of the population. While this appears to restrict the research, ‘health’ is meant in its widest sense (WHO definition - Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity).

Step 2: Contact the NILS Support Team

If you are interested in using the NILS please contact the team by emailing nils.nisra@dfpni.gov.uk, or by phoning 028 9034 8139. A member of the NILS support team will work with you to further develop your ideas. Your project will also be allocated a project number at this time.

Step 3: Attend a training session

We encourage all users to attend either a longitudinal study methods training session or an information session on the NILS.

It is not obligatory to attend one of these sessions, prior to working with the NILS. For information on forthcoming events (both NILS training sessions and more general training in longitudinal methods) see the Training and News/Events sections of the website.

The CeLSIUS website has on-line training modules and whilst these are based on theE&WLS many of the parts will be relevant to the NILS.  For further information click on CelSIUS Training.

Step 4: Complete an application form

Once you have discussed the project in detail with the NILS support team you should download and complete an application to use the NILS. You must provide some details about you and your project, including a list of the variables you require. You may also wish to attach your own data to the NILS and this must be detailed on this form. The completed form should be emailed to the NILS support team. Click on the following link to download a copy of the Application Form.

Step 5: Complete a NILS Licence Agreement 

The NILS licence agreement must be signed by the lead researcher and co-researchers working on the project. The form deals with disclosure and confidentiality issues relating to your project. This form must be posted to the NILS support team and no project can commence without this undertaking. The form can downloaded by selecting the following link: NILS Licence Agreement.

Step 6: NILS Research Approvals Group

Once the final versions of the application and undertaking forms have been received by the NILS support team, the project will then be submitted to the NILS Research Approvals Group (RAG). This group assesses whether projects should be supported and it may provide some advice on how projects could be improved. The RAG includes representatives from:

• HPSS Research and Development Office
• Northern Ireland Cancer Registry 
• Central Services Agency 
• Northern Ireland Longitudinal Study NISRA – (Census Office/General Register Office)

The criteria that the NILS RAG use to assess each project can be downloaded by selecting the following link:  RAG Criteria.

Step 7: Dataset creation

When the project has been approved, the NILS support team will begin the process of creating the user-specific sub-set of the NILS data. The creation of the dataset may require some discussions between the user and the NILS support officer before the final dataset is finalised. It is also possible for users to provide their own data to be linked to the NILS dataset. Once the dataset has been created the user will be informed.

Step 8: Analysis

All data will be analysed solely within the NILS safe-setting. The process will involve the creation of the user-specified file, which will be held in McAuley House, Belfast, where the NILS database is maintained. Users may need to visit the safe setting and analyse data alongside a NILS support officer. Results from these analyses may be released from the safe setting, once approved by the NILS support officer. Software will be made available (SPSS, STATA, LIMDEP, and the main Microsoft packages).

Step 9: Publishing / Presenting results

When you want to disseminate your NILS results beyond your project team and named associates you must obtain final outputs clearance from the NILS RAG.  A NILS Output Clearance Form must be completed and sent to the NILS team to be presented to the RAG.  This form can be downloaded by selecting the following link: Output Clearance Form. 

Typical final outputs will be working papers, reports or journal articles intended for publication, presentations or abstracts.

The NILS RAAG must clear all types of output and you should allow 15 working days for final outputs clearance although many outputs are cleared more quickly than this.

The process for clearing final outputs reduces the risk of disclosure, ensures that the study and data are properly described and that the data have been used appropriately. Key criteria that will be considered are:

• The results displayed and the discussion concerning them do not raise confidentiality or disclosure issues;
• The NILS is described correctly, drawing upon standard descriptions that we provide;
• ´Source: Northern Ireland Longitudinal Study´ is added to tables and figures, where appropriate;
• You acknowledge the support of the NILS team by including the following disclaimer:

"The help provided by staff of the Northern Ireland Longitudinal Study (NILS) is   acknowledged. The NILS is funded by the Department of Health, Social Service and Public Safety, and the Research and Development Office of the Health and Personal Social Services. The authors alone are responsible for the interpretation of the data."

Once your final output has been cleared for public release you may disseminate it a number of times without resubmitting it for clearance, as long as tables or figures are unchanged and there is no new discussion of NILS processes.

Step 10: Notify the NILS support team of publications

Please notify the NILS Support Team when a publication, which draws on the NILS, is published. We maintain a library of all published research that uses the NILS and it is vital for us to keep this up-to-date.