Use and effectiveness of physical activity and dietary based lifestyle interventions for patients with hypertension

Study type
Protocol
Date of Approval
Study reference ID
20_000180
Lay Summary

Health behaviours such as poor diet, physical inactivity, excessive alcohol consumption and smoking play key roles in the development and progression of high blood pressure (also termed Hypertension), which is an important contributor to cardiovascular disease. High blood pressure is modifiable and can be brought into remission through lifestyle interventions including maintaining a healthy diet and body weight, engaging in moderate to vigorous physical activity, reducing alcohol consumption and abstaining from tobacco smoking. Many lifestyle intervention programmes under the umbrella of social prescriptions have been developed to help people who have or are at risk of this condition. While clinical trials have pointed towards beneficial effects of lifestyle intervention, they may not fully capture real life and longitudinal effects of these interventions. It is also important to determine whether different patient groups (by sex, age, socioeconomic status and underlying health conditions) benefit from lifestyle intervention programs to the same extent. Finally, it is not known how often lifestyle interventions are used as a first line option in practice by GPs. This study focusses on the use and real-life effectiveness of lifestyle intervention programmes in UK primary care. Because of the large number of patients included in CPRD (Clinical Practice Research Datalink) and the extensive time horizon during which these patients were observed, we will be able to study immediate benefits and long-run effects for both men and women. Given the promising use of lifestyle intervention, the results of this study have direct implications for clinical care and population health.

Technical Summary

This is an observational cohort study that focuses on the patterns of use and effectiveness of lifestyle intervention programmes in UK primary care. First, this study explores the use of lifestyle interventions in UK primary care in adherence to current guidelines for hypertension, for which they are recommended as a first line option, by studying the proportion of patients who received a structured lifestyle intervention upon their diagnosis of hypertension. Second, we aim to analyze the effect of lifestyle intervention on physical and behavioral outcomes in a routine care set-up for adult men and women. We will divide the lifestyle interventions into different subgroups (i.e. physical activity-based, dietary, or pharmaceutical interventions) and will examine the effects of each intervention and each combination of interventions separately on our outcomes (i.e., blood pressure, blood cholesterol levels, BMI, smoking, hazardous alcohol consumption, mortality [by linkage to Office for National Statistics data], number of hospitalizations [by linkage to Hospital Episode Statistics data] and severe adverse health events recorded; at each follow-up time of 6 months, 1, 3, or 5 years). We aim to apply the DAME (Dynamic Almost Matching Exactly) matching approach, an advanced matching technique that weighs those covariates more which directly contribute towards the treatment effect more. Upon matching our treatment and control groups and to determine whether outcomes of patients differ between patients in each subgroup, we will apply mean comparison tests. Finally, we will test for heterogenous treatment effects by stratifying our sample by sex, age, socioeconomic status, ethnicity and comorbidities. Multiple testing is accounted for using the Benjamini-Hochberg method to take into consideration the number of subgroups and primary outcomes. The findings of this study are expected to provide novel insights into the use and effectiveness of lifestyle interventions in a real-life setting and can directly inform clinical practice.

Health Outcomes to be Measured

We will explore the effects on the following primary outcomes:
- Blood pressure
- Blood cholesterol levels (HDL, LDL, total cholesterol)
- BMI
- Smoking status
- Recorded hazardous alcohol consumption

We will also explore the following secondary outcomes
- Number of all-cause emergency hospitalizations
- Number of cardiovascular disease-related emergency hospitalizations
- Number of severe adverse health events (stroke, heart attack [myocardial infarction] – each event type evaluated separately)
- All-cause mortality
- Number of GP visits
- Number of medications

Collaborators

Till Bärnighausen - Chief Investigator - University of Heidelberg
Julia Lemp - Corresponding Applicant - University of Heidelberg
Anant Jani - Collaborator - University of Oxford
Christian Bommer - Collaborator - University of Heidelberg
Justine Davies - Collaborator - University of Birmingham
Maximilian Schuessler - Collaborator - University of Heidelberg
Pascal Geldsetzer - Collaborator - University of Heidelberg

Linkages

2011 Rural-Urban Classification at LSOA level;HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation