Manual Short Form- Health and Labour Questionnaire (SF-HLQ)

Random sample size, effect size and measurement momentsIn an economic evaluation, the minimum group size and number of measurement momentsdepends on a variety of factors. The number of respondents in a random sample depends on theexpected differences in healthcare consumption and production losses between the experimentalgroup and the control group. Furthermore, next to costs, other effect measurements are includedin an analysis of this kind (such as clinical effects, quality of life) which may be relevant to thenumber of respondents to be included. The recall period in the SF-HLQ is one month. However, ifthe respondents were absent for the complete month because of health-related problems, theyare asked when this period of absence had started. Hence, data on long-term absence iscollected.When calculating the costs, it was assumed that the period of time during which themeasurement was carried out, was representative for the period between two measurementmoments. The optimum length of time between two measurement moments, number ofmeasurements and number of respondents required depends on the difference in costs (andother effect measurements), the expected course of the disease and the treatment. Therefore itmay be desirable to adjust the recall-period. However, longer recall-periods may induce chancesof errors.ImplementationThe SF-HLQ can be conducted in writing and orally. The following options are available:• The respondent completes the SF-HLQ independently; the questionnaire is sent by e-mail ormail, or is available through the website, together with written instructions on how to completethis.• The respondent completes the SF-HLQ independently, after receiving oral instructions, bytelephone or otherwise, on how to do so.• Lastly, the SF-HLQ may be conducted by an interviewer, either by telephone or during a visitto the respondent’s home.6