This application is for two related studies which investigate how stop smoking treatment is delivered in primary care in the UK.
Study 1 (varenicline prescriptions) aims to study whether changes to the prescription information for varenicline (brand name: Champix), a licensed stop smoking medication, led to any changes in the number of times it was prescribed in primary care in the UK, to patients who smoke. ‘Black Triangle’ safety warnings are added to the prescription information of medicines when the medicine is undergoing additional safety monitoring. On the population level, we will look at whether the number of times that varenicline was prescribed each month increased or decreased significantly following the addition (July 2009) and removal (April 2006) of the safety warning label. On an individual patient level, we will look at whether the likelihood of a patient who smokes being prescribed varenicline increased or decreased significantly following the addition (July 2009) and removal (April 2006) of the safety warning label. We predict that when varenicline contained this safety warning, doctors may have been more reluctant to prescribe it.
Study 2 (e-cigarettes in primary care) aims to look at how electronic cigarette (e-cigarette) use is recorded/monitored in patient records in primary care in the UK. Currently e-cigarettes are not a medicinally licensed smoking cessation treatment but are a popular smoking cessation aid in the UK. We want to investigate whether doctors are making a note if any of their patients are using an e-cigarette or not.
This protocol is for two related studies which investigate how smoking cessation treatment is delivered in primary care in the UK and how this could be improved to reduce the prevalence of smoking, in particular in two ‘disadvantaged groups’: people of lower socioeconomic position, and people who have mental health condition(s)).
Study 1 (varenicline prescriptions) investigates the impact of two historic clinical guideline changes on varenicline (Champix), a licensed smoking cessation medication, prescription rate for patients who smoke in primary care in the UK. The guideline changes of interest are the addition of a ‘Black Triangle’ safety warning to varenicline by the European Medicine Agency in July 2009, and the subsequent removal of this safety warning in April 2016. At the population level, the monthly prescription rate of varenicline will be described between 2006 and 2020. At the clinic visit level, a regression discontinuity design will be used to test whether there was a change in the odds of receiving a prescription for varenicline during clinic visits for patients who smoke, smoke and have mental health condition(s), and smoke and are in lower socioeconomic positions, after the guideline changes.
Study 2 (e-cigarettes in primary care) investigates electronic cigarette (e-cigarette) use recording in primary care electronic healthcare records in the UK. Currently e-cigarettes are not a medicinally licensed smoking cessation treatment but are a popular smoking cessation aid in the UK. This exploratory study will describe how codes for recording e-cigarette use (Read codes, SNOMED) have been used since their inception in the 2010s and how this has changed over time, and in relation to patient characteristics such as age, sex, socioeconomic position, ethnicity, presence/absence of mental health condition(s), and a measure of chronic illness. We will also calculate an estimate of e-cigarette use prevalence per year, as recorded in CPRD.
Study 1 (varenicline prescriptions): monthly rate of varenicline prescribing at the population level; odds of receiving a varenicline prescription at a clinic visit where the patient has a ‘current smoker’ smoking status.
Study 2 (e-cigarettes in primary care): cumulative proportion of patients who have a SNOMED code related to e-cigarettes in their patient record, over time.
Leonie Brose - Chief Investigator - King's College London (KCL)
Bernadett Tildy - Corresponding Applicant - King's College London (KCL)
Alex Dregan - Collaborator - King's College London (KCL)
Ann McNeill - Collaborator - King's College London (KCL)
Sol Richardson - Collaborator - King's College London (KCL)
Leonie Brose - Collaborator - King's College London (KCL)
Patient Level Index of Multiple Deprivation