Health and Care of People with Learning Disabilities, Experimental Statistics 2023 to 2024

The proportion p is given by \(p = \frac{O}{n}\)

where: 

O is the numerator observed number of individuals in the sample/population having the specified characteristics.

n is the denominator total number of individuals in the sample/population.

 The 95% confidence intervals are given by

\(p_{lower}=\frac{(2O+z^2-z\sqrt{z^2+4Oq})}{2(n+z^2)}\)

\(p_{upper}=\frac{(2O+z^2+z\sqrt{z^2+4Oq})}{2(n+z^2)}\)

where: q is 1-p

z is the 97.5th percentile of the Standard Normal Distribution (1.96)

Indirectly standardised rate (ISR) is given by

\(ISR=\frac{O}{E}\times 100 = \frac{\sum O_{ij}\\_{ij}}{\sum E_{ij}\\_{ij}}\times 100 = \frac{\sum O_{ij}\\_{ij}}{\sum n_{ij} \lambda_{ij}\\_{ij}}\times 100\)

where

O_ij is the observed number of events in the subject population for each combination of age group i and sex j

E_ij is the expected number of events in the subject population for each combination of age group i and sex j

n_ij is the number of individuals in the subject population for each combination of age group i and sex j

λ_ij is the crude age-specific rate in the standard population for each combination of age group i and sex j

The 95% confidence intervals are given by

\(ISR_{lower}=\frac{\text{O }_{ lower}}{E}\)

\(ISR_{upper}=\frac{\text{O }_{ upper}}{E}\)

where

O_lower and O_upper are the lower and upper confidence limits for the observed number of events.

The presence of small numbers, combined with reasonably granular age and sex and in some cases ethnicity breakdowns, presents a risk of identification and/or self-identification. Data also pertains to sensitive information such as mental health.

As such, within the sub ICB level csv file the following suppression rules will be applied:

1. Zeros remain as zero

2. Counts 1 to 4 rounded to 5

3. Counts > 4 rounded to the nearest 5.