Developing Evidence Based Optimal Testing Strategies To Monitor Long Term Conditions In Primary Care

Summary

Patients with long term conditions (LTC) have regular monitoring appointments including blood tests. The evidence base for current testing recommendations is weak because measuring patient benefits or harms of regular monitoring is challenging. The aim of this project is to develop a methodology for creating evidence-based testing strategies to monitor people with LTCs and accompanying patient and clinician materials.

Introduction

Most patients with long term conditions (LTC) receive regular blood tests to monitor disease progression, response to treatment, and detection of complications. There is currently no robust evidence to inform recommendations on monitoring. Creating this evidence base is challenging because the benefits and harms of testing are dependent on what is done in response to the test result.

Methods 

We identified a list of commonly used tests. We defined a series of filtering questions to determine whether there was evidence to support the rational of monitoring, such as ‘can the GP do anything in response to an abnormal test result?’. Through a series of rapid reviews we identified evidence to answer each question. The evidence was presented at a consensus meeting where clinicians and patients voted for inclusion, exclusion, or further analysis. A process evaluation was performed alongside this. Further analyses are performed using routinely collected healthcare data, by performing incidence analyses, emulating RCTs, and modelling disease progression.

Results 

We tested this methodology on three common LTCs chronic kidney disease (CKD), type 2 diabetes mellitus (T2DM, and hypertension. We found sufficient evidence to include HbA1c and eGFR for monitoring T2DM patients; hemoglobin and eGFR for CKD; and eGFR for hypertension. The consensus panel excluded four tests; however, ten tests were selected for further analyses which are still ongoing. The emulated RCTs aim to investigate the effect of regular testing with certain tests on patient outcomes among routinely monitored patients. In addition, we will investigate the signal to noise ratio of each test over time using a modelling approach.

Conclusions 

The cost-effectiveness of the evidence-based testing panels need to be tested in clinical practice. We currently developing an intervention package and are planning to run a feasibility trial. This programme of work has the potential to change how LTCs are monitored in primary care, ultimately improving patient outcomes, and leading to more efficient use of healthcare resources.