Study type

Study type

Non-interventional study

Scope of the study

Assessment of risk minimisation measure implementation or effectiveness
Disease epidemiology
Drug utilisation
Effectiveness study (incl. comparative)
Non-interventional study

Non-interventional study design

Cohort
Case-control
Cross-sectional
Study drug and medical condition

Anatomical Therapeutic Chemical (ATC) code

(N05CF) Benzodiazepine related drugs
Benzodiazepine related drugs

Medical condition to be studied

Dementia
Insomnia
Population studied

Age groups

Adults (65 to < 75 years)
Adults (75 to < 85 years)
Adults (85 years and over)

Estimated number of subjects

21000
Study design details

Main study objective

Using existing data we will look at whether Z-drugs improve sleep, whether they improve quality of life for people with dementia and their carers and how they affect memory and thinking during the day or other behavioural problems.

Outcomes

Incident (a) fracture (any location) (b) hip fracture (c) forearm fracture. Hip fracture recording in CPRD has been well validated (PPV of 91%).Incident fall. GP records of falls may under-represent all falls that occur in the older population, but more accurately represent ‘injurious falls requiring medical attention’. Mortality.Infection. Respiratory tract infection has been validated in CPRD (PPV of 97%).

Data analysis plan

We will use the Cox proportional hazard model to estimate the effect of covariates on time to first prescription of each class sleep medication since dementia diagnosis. Sleep medication will be treated as a time-varying variable. Then we will use the multinomial regression model to estimate the effect on treatment choice conditional on the sleep disturbances, after controlling for potential confounders, allowing non-linear effects and interaction between confounding variables and time-varying ones.