Health Informatics and Evidence-based Practice

The Efficacy - Effectiveness Gap

The lecture discusses the gap between efficacy and effectiveness in medical treatments.
Efficacy: The power or ability to produce an effect, best tested using randomized controlled trials (RCTs).
Effectiveness: The degree to which something successfully produces a desired result, best tested in 'real-world' trials.
Efficacy-Effectiveness Gap: Differences in outcomes between patients treated in RCTs (ideal conditions) and those in real-world settings (messy conditions).

RCTs are experiments designed to reduce bias when testing treatment efficacy.
They involve:
- Random allocation of subjects to groups.
- Different treatments, with comparison of responses.
- An experimental group receiving the intervention (e.g., a drug).
- A control group receiving an alternative (e.g., a placebo).
- Monitoring the groups to determine the efficacy of the experiment.
Strengths of RCTs:
- Accurate, unbiased measurement of treatment effect.
- High degree of internal validity.
- Strict eligibility criteria leading to a homogenous study population.
- Reduced inter-patient variability.
Limits of RCTs:
- Suboptimal representation of real-world patients, especially those with advanced age or greater comorbidities.

Alternative to RCTs.
Employ less restrictive recruitment criteria to ensure representation of individuals with previously ineligible characteristics.

Implementation Science: The study of methods for integrating research and evidence-based interventions into routine clinical practice.
Research funders are increasingly interested in seeing successful treatments implemented without delay.
Key aspects for successful implementation:
- Being prepared.
- Communicating effectively.
- Ensuring required resources are available.
- Enlisting needed help.
- Using resources efficiently.

Context: Prescribing of antibiotics, particularly for respiratory infections.
Issues:
- Questionable effectiveness in respiratory infections.
- Association with increasing bacterial resistance.
- Associated with preventable deaths in hospital, can be costly, and has side effects.
Example Study: Amoxicillin for acute lower-respiratory-tract infection in primary care.
- A 12-country, randomised, placebo-controlled trial published in The Lancet (2013).
- DOI: 10.1016/S1473-3099(12)70300-6
- Conclusion: Amoxicillin provides little benefit for acute lower-respiratory-tract infection in primary care when pneumonia is not suspected clinically and may cause slight harms.
BMJ Open Study: Serious bacterial infections and antibiotic prescribing in primary care.
- Conclusion: No population-level evidence that family practices with lower total antibiotic prescribing might have more frequent occurrence of serious bacterial infections overall.
- Improving the recording of infection episodes could inform better antimicrobial stewardship in primary care.

Individual clinician (investigation, prescribing, non-drug interventions).
Local groups (hospital teams, general practices, community teams).
Professional groups (paediatricians, infectious disease clinicians, public health clinicians).
Organisation.
Region.
Society.

Facilitators:
- Experienced leadership.
- Detailed planning.
- Team engagement.
- Prioritisation.
- Provision of required resources.
Obstacles:
- Lack of commitment by management.
- Disorganised work culture.
- Poor readiness to change.
- Poor team structure.

Implementing research evidence to improve health outcomes.
Preventing harm from discredited treatments by implementing research evidence against them.