The Cost and Intermediate Cost-Effectiveness of a Randomized Control Trial Delivering U=U Messaging to Increase HIV Testing Among South African Men.

Chronic Obstructive Pulmonary Disease (COPD) is one of the most common chronic respiratory diseases worldwide, characterized by progressive and irreversible airway obstruction and chronic inflammation. Its main symptoms include dyspnea, chronic cough, and sputum production []. According to the World Health Organization, more than 213 million people globally were affected by COPD in 2021 []. In Iran, based on the Global Burden of Disease (GBD) project, the age-standardized prevalence of COPD has been reported at approximately 5,155 per 100,000 population []. COPD is one of the leading causes of mortality worldwide and is expected to become the third leading cause of death globally by 2030 []. Due to its chronic and complex nature, successful management of COPD cannot be achieved solely through medication prescription; it also requires the patient’s active and informed participation in the care process. In this context, health literacy plays a crucial role. Health literacy refers to an individual’s ability to obtain, understand, and apply health information, and it directly influences self-care behaviors, including medication adherence [, ]. Several studies have shown that patients with COPD and low health literacy often struggle with the correct use of inhaled medications and tend to have lower adherence to treatment regimens [, ]. Additionally, cognitive decline—such as reduced mental processing speed—which is common among these patients, further exacerbates difficulties in regular medication use, particularly when combined with limited health literacy []. Moreover, high comorbidity rates among COPD patients must be considered. More than three-quarters of individuals with COPD suffer from at least four other chronic conditions, which complicates their medication regimens and increases the risk of medication errors [, ]. As a result, treatment adherence in these patients is often poor; studies report non-adherence rates to inhaled medications ranging from 30% to 68% [–].