The list of GP consultations available in the GPRD data were classified into these four types of consultation, and the unit costs for each type of consultation were derived from the Unit Costs of Health and Social Care 2009 (Table 1).
GP consultation data derived from the CPRD, which is the largest anonymised primary care database in the UK [ 14], drawn from clinical and prescribing records recorded general practitioners within their practices.
The costs per consultation were derived from the results of a recent cohort study (17) which compared the NHS and patient medication costs for an index consultation and 2-week follow-up, for patients deemed to have symptoms suggestive of minor ailments who presented in community pharmacies, EDs and general practices.
Costs of outpatient and hospital paediatric consultations were derived from price lists for public health services in the Autonomous Community of Madrid [ 27].
The standard error and 99.9% CIs for the parameter relating to the number of general practice consultations were derived from the simple linear regression with financial year coded as a continuous variable; a quadratic term was not statistically significant when added to the regression equation to explore nonlinearity (P = 0.18).
Our approach in this regard coincides with that of Rong and Ling (2008), who state that the proposals for ICT competence and literacy models and elements based on standards and derived from consultation processes with experts or Delphi techniques provide the dimensions and competences that need to be included therein.
The consultation costs estimates were derived from the cohort study mentioned above.
Morbidity data were derived from consultation diagnoses and furthermore from all prescriptions issued by the participating practices.
The incidence rates for common opioid-induced side effects associated with each drug were derived from consultation of the expert panel of oncologists (Table 2).
One year after the reminder was mailed to the last patient in the cohort, each dermatologist was mailed a table summarising the data to be collected for each patient, including the date of the dermatological consultation and the conclusion derived from the skin examination, that is, 'benign lesion', 'lesion to monitor' or 'indication for exeresis'.
