Inclusion/Exclusion Criteria in COPD Study

Inclusion/Exclusion Criteria

• Inclusion criteria for a study often include demographic, clinical, and geographic characteristics
• Exclusion criteria are features of potential participants who meet inclusion criteria but have additional characteristics that could interfere with the study's success.
• Common exclusion criteria include characteristics of eligible participants that make them highly likely to be lost to follow-up.
• Exclusion criteria address issues like missing appointments, inaccuracies in data collection, and comorbidities that could bias results.
• Inclusion criteria ensure participation and research is conducted appropriately.
• Exclusion criteria ensure a study population that aids good research/evaluation.

A Study to Assess Prevalence of Malnutrition in Patients with COPD

• Inclusion criteria for COPD patients: adults 40+ years of age with a COPD diagnosis for a year or more, at least one post-bronchodilator FEV1/FVC less than 0.70 result in spirometry in the prior year, current or former smoker with more than 10 pack-years, and stable disease with no recent exacerbation events.
• Exclusion criteria for COPD patients: diagnosis of sleep apnea and other chronic respiratory diseases, any acute or chronic condition that may limit participation, refusal to provide informed consent.

Feasibility Considerations

• Access to research study participants, with their desired demographic and clinical characteristics.
• Likelihood of participant participation, adherence to the study protocol.
• Ethical considerations include randomization (placebo), adverse event rates, burden on participants, vulnerable participants and representativeness.
• Timing for the intervention: such as acute, post-event, pre-event, etc.

Impact on Outcomes

• Event outcomes lead to morbidity and mortality.
• Surrogate/biomarker outcomes relate to cholesterol levels and cognitive scores.
• Patient-specific outcomes involve pain, symptoms, quality of life and rated health.
• Composite outcomes address multiple components.

How Does Participant Selection Influence Outcomes?

• Feasibility of measuring intended outcomes given participant characteristics.
• How participant characteristics may change during a trial.
• Participants' capacity to describe dietary intake.

Factors to Consider in Participant Characteristics

• Entry criteria include the target of the intervention, such as an individual, a caregiver, or a community.
• Inclusionary and exclusionary characteristics for selection.
• Recruitment and retention strategies.
• Study selection should adhere to scientific principles and regulatory requirements.

Entry Criteria: Purpose

• Inclusion criteria target participants relevant to the study outcomes.
• Participant disparity must be balanced.
• Exclusion criteria prioritize concerns of safety, confounding factors, and feasibility

When Should Entry Criteria Be Determined?

• Criteria should be determined early in the study before recruitment, IRB approval, and funding to minimize bias.
• Specificity is essential in the criteria definition.
• Entry criteria should not be changed after the start of the study.

Patient Selection - Context

• Causal relationships are context dependent in research.
• Personal experiences (consent), social environment, and cultural considerations are vital to research design.

Patient Selection - Access

• Access considerations for participants should begin early in planning phases.
• Building interdisciplinary teams is often necessary.
• Recruit from multiple study sites, not just the researchers' own practice.

Recruitment and Retention

• Recruitment and retention are critical to the success of a trial.
• Respondent/participant burden associated with assessments and treatment.
• Treatment complexity, intensity and duration influence retention.
• Ensuring participant health, logistics (e.g. transportation) and representativeness.

Improving Recruitment

• Utilize multi-faceted recruitment strategies, including community-based, social marketing, mailings, presentations at health fairs, referrals, and well-managed recruitment goals.
• Run-in periods help to ensure participant acceptability.
• Strategies to ensure representation in the sample.

Improving Retention

• Managing participant burdens by minimizing requirements for study components.
• Optimized study visit schedules that are convenient, efficient, with culturally competent staff and attentiveness.
• Eliminating accessibility barriers like transportation, childcare, gas costs.
• Incentivizing suitable participation.
• Scheduling/sending reminders for appointments.
• Arranging appointments at the beginning of the study window.

Adherence

• Measuring adherence includes diaries, pill counts, blood tests, accelerometers, pedometers, pictorial food logs, and using microchips when possible.
• Optimizing adherence: implementing motivational interviewing, providing orientations and outlining expectations, establishing communication channels, and ensuring transparency and accountability.
• Maintaining contact through back-up methods, such as phone calls, birthday cards, newsletters, and retention events.
• Considering selecting participants based on run-in data for an assessment of potential adherence.

Common Errors

• Defining variables used for inclusion/exclusion criteria should be consistent.
• Criteria selection should be relevant to study subject matter/questions to be answered.
• Clarify inclusion criteria that are crucial for understanding external validity results.

Strict Inclusion Criteria Examples

• High protein diet in Type 2 diabetes: patients with BMI 30-35 kg/m², aged 40-60, and Type 2 diabetes for at least 5 years, who aren't on insulin therapy.
• Omega-3 supplementation in mild cognitive impairment: aged 65-75, MCI diagnosis, no CVD history, and no other dietary supplements.

Loose Inclusion Criteria Examples

• Dietary patterns linked to cardiovascular disease: participants of diverse backgrounds and varying dietary habits (aged 18-80).
• Plant-based diet effects on weight loss: any adult willing to follow a plant-based diet for 12 weeks, with diverse characteristics.

Per Protocol vs. Intention-to-Treat (ITT)

• Per-protocol analysis focuses on subjects who completed the study as intended, often overestimating benefits.
• ITT analysis focuses on all subjects who were initially assigned to a group, providing a more realistic representation of treatment effects.
• ITT is the preferred analysis method because randomizations can't cause confounding.
• Ideally, per protocol and ITT populations would match.