Conference Coverage

Higher ZIP Code Income Linked to Lower Postoperative Pain in Cohort Study

Edited by:
Brian McCurdy

Key Highlights

  • Each $100,000 increase in ZIP code median income was associated with approximately 0.29 points lower maximum pain on a 0–10 scale.
  • The analysis adjusted for age, BMI, insurance type, gender, and perioperative opioid administration.
  • Researchers estimated socioeconomic status using neighborhood median income rather than individual earnings.
  • The findings are scheduled for presentation at Anesthesiology 2026 in San Diego, California.

In a retrospective study of 3,992 adults undergoing surgery at Stanford Medicine hospitals, higher median income in a patient’s home ZIP code was associated with lower maximum postoperative pain, according to an abstract scheduled for presentation on October 17 at Anesthesiology 2026.

Investigators evaluated whether socioeconomic status, estimated through ZIP code median income, was associated with the highest pain score reported after surgery. Their adjusted model linked a $100,000 increase in neighborhood median income to approximately 0.29 points lower maximum pain.

Researchers examined electronic health records for surgical patients receiving general anesthesia between September 2009 and September 2024. They randomly sampled 7,009 patients and analyzed only each patient’s first surgical admission. ZIP codes were linked to 2022 US Census Bureau median income estimates using ZIP code tabulation areas and mapping data from the Health Resources and Services Administration.

The primary outcome was maximum postoperative pain measured on a numeric rating scale from 0 to 10. The perioperative window extended from propofol initiation through postanesthesia care unit discharge. A multivariable linear regression model adjusted for age, BMI, insurance type, gender, and perioperative opioid dosage expressed in morphine milligram equivalents (MME).

Study Findings

Researchers excluded 3,017 patients because of incomplete records, age younger than 18 years, or exclusion criteria involving prior narcotic use, alcohol or intravenous drug abuse, or a chronic pain diagnosis. The final cohort had a mean age of 57.5 years (SD, 16.5); 48.2% were female, and 71.5% were White. The abstract reported an average ZIP code median income of $134,069 (IQR, $90,094–$177,365), an average opioid dose of 20 MME (IQR, 5–27.5), and an average maximum pain score of 4 (IQR, 0–7).

Higher ZIP code median income was negatively associated with maximum postoperative pain, with an estimated regression coefficient of −2.874 × 10⁻⁶ points per dollar (SE, 9.286 × 10⁻⁷; P < .002). According to the authors’ model, an approximately $348,000 increase in median income corresponded to a 1-point decrease in maximum pain.

Clinical Implications

The authors characterized the modeled association as meaningful at the population level. They suggested that socioeconomic status could influence clinical pain-management decisions or patients’ perception of pain, potentially affecting reported postoperative pain, management, and opioid dependency.

Expert Commentary

“Our results indicate that there is an association between a patient’s socioeconomic status and their maximum postoperative pain,” the researchers concluded.

Reference

Sydloski J, Mather RV, Johnson JJ, Gutierrez R, Purdon P. Does income matter? The association of median income by zipcode with postoperative pain. Abstract scheduled for presentation at: Anesthesiology 2026; October 16–20, 2026; San Diego, CA. Abstract A1722.