Economic drivers and systemic disparities in invasive coronary angiography: Insights from a national claims database.

The majority of invasive coronary angiography (ICA) hospitalizations in Iran were for non-acute indications, with acute coronary syndrome accounting for 17.0% of episodes.

• Data from 158,584 hospitalizations were analyzed from the Iran Health Insurance Organization (IHIO) database.
• 17.0% of episodes pertained to acute coronary syndrome.
• The remaining 83.0% were for chronic or other indications.

The median inpatient cost for ICA hospitalization was PPP$2033, with interventional services accounting for the largest share of costs.

• Median inpatient cost was PPP$2033.
• Interventional services accounted for the largest share of costs at 37.1%.
• Out-of-pocket expenditure was 16.6% of total costs.

Procedure complexity was the major predictor of inpatient costs, with a cost ratio of 4.37.

• Procedure complexity had a Cost Ratio of 4.37 (95% CI 4.34–4.39).
• Private ownership, heart center status, and weekend hospitalization were also significant predictors of costs.
• Three-tier (patient, hospital, and province) generalized linear mixed models were used to model inpatient costs.

Revascularization was performed in nearly half of all ICA hospitalizations, with male sex and older age associated with higher revascularization odds.

• Revascularization was performed in 47.2% of hospitalizations.
• Male sex and older patients had higher revascularization odds, prolonged stays, and incurred higher costs.
• Less deprived provinces had higher revascularization odds for chronic indications, indicating socioeconomic disparities in treatment.

Ambient pollution, lower socioeconomic deprivation, and higher healthcare capacity were associated with higher provincial ICA rates.

• A multi-pollutant index was constructed using weighted quantile sum regression.
• Higher capacity in terms of active beds and angiography devices was associated with higher provincial ICA rates.
• Lower socioeconomic deprivation (i.e., more affluent provinces) was also associated with higher provincial ICA rates.
• Ambient pollution exposure was an additional factor associated with provincial ICA rates.

Non-cardiac hospitalizations were associated with prolonged length of stay compared to cardiac hospitalizations.

• Non-cardiac hospitalizations had prolonged length of stay (LOS).
• LOS was modeled using three-tier generalized linear mixed models accounting for patient, hospital, and province levels.
• Male sex and older age were also independently associated with prolonged stays.

Systemic disparities in ICA utilization exist across Iranian provinces, driven by regional capacity and socioeconomic factors.

• Hospital case volume and provincial ICA rates were modeled using generalized linear models.
• Provinces with higher numbers of active beds and angiography devices had higher ICA rates.
• Less deprived (more affluent) provinces had higher revascularization odds for chronic indications, suggesting unequal access to elective cardiac procedures.

Private hospital ownership and heart center status were significant institutional predictors of higher inpatient costs.

• Private ownership was identified as a significant predictor of higher costs in the three-tier generalized linear mixed models.
• Heart center status was also independently associated with higher inpatient costs.
• Weekend hospitalization was an additional institutional characteristic associated with higher costs.