Rise in Drug Use–Related Hospitalizations for Endogenous Endophthalmitis

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Between 2003 and 2016, the United States saw a 4-fold increase in drug use–related endogenous endophthalmitis hospitalizations, contributing to a substantial health care use burden.

Between 2003 and 2016, the United States saw a 4-fold increase in drug use–related endogenous endophthalmitis hospitalizations, contributing to a substantial health care use burden. Results from the nationwide, retrospective cross-sectional study were published in JAMA Ophthalmology.

Endogenous endophthalmitis is an uncommon intraocular infection that can lead to potentially devastating visual consequences, according to the American Academy of Ophthalmology (AAO).

About half of reported cases of the condition are caused by bacteria and the other half by fungi, the AAO states, and major risk factors include “immunocompromised states (for example, chronic corticosteroid use, malignancy, end-stage liver/renal disease, organ transplant, diabetes mellitus), intravenous (IV) drug use, indwelling catheter, or dental procedures.”

Endogenous endophthalmitis has also been reported in healthy individuals, albeit rare. The condition accounts for 2% to 15% of all cases of endophthalmitis. Due to the ongoing opioid crisis in the United States, IV drug use has evolved into an important risk factor for the condition, JAMA authors explained.

Using data from the Nationwide Inpatient Sample (NIS), researchers analyzed endogenous endophthalmitis–related hospitalizations in the United States, investigated national and regional trends in hospitalizations among the drug-using population, and compared infectious and noninfectious comorbidities among those with and without drug dependance or use.

The NIS, part of the Healthcare Cost and Utilization Project, is the largest all-payer inpatient database in the country and contains data from around 7 million hospital discharges per year. In the study window, there were an estimated 56,839 endogenous endophthalmitis–related hospitalizations in the country; 13.7% (n = 7783) of individuals had a history of drug dependance or use.

The mean (SD) age of the entire cohort was 56.4 (0.25) years, and the majority (61.8%) of those in the drug-using population were men. Mean age in the drug-using cohort was also lower (49.6 years vs 57.5 years; difference, 7.9; 95% CI, 6.93-8.88; P < .001), with most such cases presenting in the fifth decade of life, authors wrote. Of the whole cohort, 55.6% were White, 13.6% were Black, and 10.6% were Hispanic.

Analyses revealed:

  • The incidence of endogenous endophthalmitis associated with drug dependence or use increased from 0.08 per 100,000 in 2003 to 0.32 per 100,000 population in 2016 across all 4 US geographic regions.
  • The highest frequency of overall admissions was from the South (38.8%; n = 22,054), followed by Midwest (22.3%; n = 34,729), West (20.2%; n = 11,481), and Northeast (18.7%; n = 10,629).
  • The drug-using population had a higher proportion of self-payers (13.5% [n = 7673] vs 3.9% [n = 2216]), and most frequently belonged to the lowest income quartile (37.4% [n = 21,258]; 0-25th median income quartile).
  • The total incidence of endogenous endophthalmitis–related hospitalizations in the United States was 1.3 per 100,000 population between 2003 and 2016; incidence peaked in 2008 (1.6 per 100,000 population) and declined to a low in 2013 (0.8 per 100,000 population) before increasing again through 2016.
  • Approximately 17.7% of all patients had a diagnosis of bacteremia (3.3%), fungemia (3.1%), or sepsis (11.3%).
  • Prevalence of bacteremia and fungemia was higher in the drug-using population, whereas sepsis rates were comparable between the 2 cohorts.
  • The 4 most common systemic risk factors associated with endogenous endophthalmitis were diabetes (27.6%), malignancy (19.2%), chronic kidney disease (14.2%), and drug dependence or use (13.7%).
  • The mortality rate in the drug-using population was 1.8% compared with 3.6% in the non–drug-using population.

In addition, data showed that median inflation-adjusted cost per hospitalization was $14,593 while the cumulative cost of all hospitalizations was estimated at $134 million. For the drug-use cohort specifically, median cost per hospitalization was $13,560, adding to a cumulative cost of around $33.6 million.

Currently, drug dependence, and opioid use in particular, affects around 19.7 million individuals in the United States and costs the US economy $740 billion each year. The finding that patients with drug use–related endophthalmitis were younger “has implications because disease burden at a younger age may incur high lifetime health care spending, increased health care services or resource use, and loss of work productivity,” researchers wrote. “In addition, subgroup analysis revealed that most of these cases belonged to the lowest income quartile, making them less equipped to deal with the ensuing visual disability.”

Because inpatients may have been reluctant to divulge opioid use or dependence, the study may have underestimated incidence of use, marking a limitation. Furthermore, study data are only through 2016, and it may be difficult to determine with certainty how results apply to considerations in 2020.

“While these findings do not aid in the management of this condition, they do support the hypothesis that clinicians should maintain a high index of suspicion for endophthalmitis when evaluating patients with intraocular inflammation in the setting of drug dependence or use,” authors concluded.


Mir TA, Papudesu C, Fang W, and Hinkle DM. Incidence of drug-use related endogenous endophthalmitis hospitalizations in the United States, 2003 to 2016. JAMA Ophthalmol. Published online November 5, 2020. doi:10.1001/jamaophthalmol.2020.4741