Information by Design
Lifestyle Survey Toolkit

Below are some of the questions you are likely to ask yourself when planning a lifestyle survey;

1.  What are the main things I need to think about in designing the survey?

Your survey results may be used to inform important policy decisions.  It is therefore important to do the survey well!  Important things to consider are;

  • The survey method to use – some methods can give better quality data, but may cost more.
  • Representativeness – your sample of responding people should be a representative sub-set of the
    whole population.  Choose appropriate sampling methods and safeguards to avoid getting a biased sample.
  • Getting the scope and objectives of the survey clearly defined and agreed.
  • The questions to ask – try not to ‘re-invent the wheel’ when designing questions.  Use tried and tested questions where available; and ones that allow you to compare your area to the national picture or to other areas.

2.  How big a sample size should I have?

Sample size usually depends on a few key factors;

  • The ‘accuracy’ you want to obtain from the survey
  • The variability in the population
  • The need for results for various sub-groups of the population.

For general population surveys, many people say that you should choose a sample of 1000 respondents so that you get data to within +/- 3% of the true population figure.  So, for example, if I use a survey of 1000 people in a Trust and find that 30% of them smoke, I can be fairly sure (95% confident) that the result is within +/- 3% of this – so, between 27% and 33%.

If however, I want to be able to look at the proportion of people who smoke in more detail and find the percentage of each age group, for men and women who smoke, then, with 5 age groups I may only get 100 men and 100 women in each age group (1000 respondents, 10 cells).  This gives us less accuracy – but in this case is probably still ok.

A general ‘rule of thumb’ is to have ‘cell sizes’ of a minimum of 30-50.

3.  How much will it cost?

The cost of the survey depends on many factors, including;

  • The sample size
  • The data collection method
  • The length of the questionnaire
  • Whether you use external consultants

 In general, the larger the survey, the more the cost…But, a survey twice as large should cost twice as much – there are some fixed costs, and some variable costs.

As an example, a postal survey of 1000 residents could cost from 6000 upwards depending on the number of reminders issued, questionnaire length etc.

4.  How should I choose my sample of who to include in the survey?

Sampling based on probability (where you choose people to include from a list or sampling frame) is best – but may not always be possible.  Cost or the availability of a suitable and accessible sampling frame may be a problem.

If your chosen survey method is to collect data by conducting interviews with residents, then it is expensive to select individual names at particular addresses, visit the house, find them in and conduct the interview.

An alternative is sampling not based on probability.  The main thing to remember here is to fix quota controls to ensure you get a sample that looks like the population (a representative sample).

5.  What If I can't afford to carry out a Lifestyle Survey?

Lifestyle surveys are an important source of data at a local level and it is important that resources are made available to conduct them.  Partnership working, for example thorough local Strategic Partnerships, provides a good opportunity to Share the cost of a survey.

However, if resource cannot be found, there are a number of options: