Quality and response rates

We do all we can to maximise response rates for the surveys. This includes:

• Mailing out as soon as possible so that patients can remember what happened
• Validating all addresses
• Leaving the fieldwork open as long as possible to allow as many people as we can to respond
• Addressing covering letters to people by name rather than "Dear Patient"
• Using colour logos on letters and questionnaires
• Providing help in 20 languages other than English
• Providing Freephone support
• Offering internet completion of questionnaires

However, we can't always get as high a response rate as we would like. Response rates tend to be higher for questionnaires that are more disease specific - for example, our best response rate was for a Coronary Heart Disease survey (78%). We also get better response rates if the questionnaire is about a recent healthcare experience rather than one that happened a long time ago. Older people are much better at responding than young people - young men have the lowest response rate. We also get a worse response rate in cities, particularly London, where there are more "multiple occupancy" houses and where people tend to move house more often.