The dataset source, Public Health England, is an executive agency of the Department of Health & Social Care, part of England Government.
The NHS Health Check program is a health check-up for adults in England aged 40-74 years old, designed to spot early signs of stroke, kidney disease, heart disease, type 2 diabetes or dementia. Persons existing disease registers, having one of the mentioned types of diseases, are not eligible. Each eligible person aged 40-74 should be offered a NHS Health Check once in every 5 years and each person should be recalled every 5 years if they remain eligible. The dataset is providing percentages estimates for each financial year, for each financial year quarter and for 5 years cumulative percentages of the eligible population offered an NHS Health Check (persons invited), received an NHS Health Check and of the invited persons who received an HHS Health Check.
The numerator data, provided by Public Health England (from Health Checks data collection) is divided by the number of eligible population and multiplied by 100.
The confidence intervals are calculated using the Wilson Score method for the percentages of persons invited and of persons who received an NHS Health Check and based on Byar’s method, for the percentages of persons invited who received the health check. The Wilson Score method is the preferred method for calculating confidence intervals for proportions and odds, but it can also be used for rates, as long as the event rate is low (relatively rare events within the population) as the Binomial distribution is a very good approximation to the Poisson distribution when the event rate is low. Byar’s method is the preferred method for calculating confidence intervals for counts, crude rates, indirectly standardized rates and indirectly standardized ratios, but it can also be used for proportions, as long as the proportions are small (much closer to zero than to one) as the Poisson distribution is a very good approximation to the Binomial distribution when the proportion being measured is small.