The test retest reliability of questions used in the predictD studies has been reported previously [ 62, 71].
The results of this pilot study and the validity and reliability of questions were taken into consideration when modifying the questionnaire to produce the final version [ 27].
The reliability of questions structured on nominal or ordinal scales was tested employing Cohen's kappa and interval scale responses were checked by intra-class correlation.
Papers have addressed the reliability of questions in telephone health survey questionnaires conducted by the Behavioral Risk Factor Surveillance System (BRFSS) in the United States [ 1- 6].
The reliability of questions was assessed by a test-retest study on a group of forty class six adolescents and calculating the Pearson's reliability coefficient (r) which was found to be 0.79 for the questionnaire and 0.87 for the interview questions.
The aim of this study is to compare the reliability of questions asked in the SAMSS by conducting a test/retest analysis of a range of questions covering demographic variables, health risk factors and chronic conditions variables among people aged 16 years and over.
Data used in the planning and monitoring of health services and disease prevalence in populations should be as accurate as possible and assessing the reliability of questions is one way that accuracy or precision of the questions can be assessed and bias minimised.
This study examines the reliability of questions asked in a telephone survey by conducting a test/retest analysis of a range of questions covering demographic variables, health risk factors and self-reported chronic conditions among people aged 16 years and over.
Table 1 gives a breakdown of the respondents and their job descriptions:> The Cronbach Alpha for each main role was above 0.8 (see Table 2), which means that the internal consistency/ reliability of questions combined for each main role was excellent.
ASA, American Society of Anesthesiologists; SAPS II, Simplified Acute Physiology Score; ICU, Intensive Care Unit ORR, odds ratio *Adjusted to age, gender, ASA, type and magnitude of surgery, ICU LOS, marital and employment status The internal reliability of questions in each domain ranged from 0.80 to 0.93.
