A retrospective analysis of electronic health records revealed that patients with chronic cough were approximately twice as likely to be prescribed opioid-containing cough suppressants compared to those without chronic cough.

The research, published in Therapeutic Advances in Respiratory Disease, analyzed data from 23,210 patients with chronic cough and 229,538 patients without chronic cough.

Key Findings

• 21% of chronic cough patients received opioid-containing cough suppressants (OCCS) prescriptions within 1 year of their diagnosis.
• Odds of receiving an OCCS prescription were 2.0 times higher for chronic cough patients (95% confidence interval [CI] = 1.88-2.08) vs non–chronic cough patients.
• Medicaid recipients were 2.76 times more likely to receive OCCS prescriptions (95% CI = 2.62-2.91) than those with other types of insurance coverage.
• 34% of chronic cough patients received at least 3 OCCS prescriptions, while 0.5% of chronic cough patients received more than 10 OCCS prescriptions.

Methods

Researchers conducted a retrospective cohort study using electronic health records from the Indiana Network for Patient Care, representing over 100 hospitals and 13.5 million patients. The study included adults aged 18 to 85 years who received care between October 2005 and September 2015.

Chronic cough was defined as at least three medical encounters with cough, with 56 to 120 days between the first and last encounter. Cough was identified through natural language processing, diagnostic codes, or prescriptions for benzonatate or dextromethorphan.

OCCS were defined as drugs containing codeine, dihydrocodeine, or hydrocodone. Researchers used zero-inflated Poisson models to analyze prescription patterns, adjusting for demographic factors and insurance status.

Further Results

The chronic cough cohort (n=23,210) differed significantly from the non–chronic cough group (n=229,538):

• Higher proportion of women (66% vs 61%)
• More Medicare recipients (36% vs 24%)
• Older mean age (54 vs 48 years)
• Higher proportion of White patients (72% vs 69%)
• 17% African-American patients in the chronic cough cohort
• 31% commercial insurance and 19% Medicaid insurance rate in the chronic cough cohort.

The median number of encounters for chronic cough patients was 85 (range = 45-151), with a median follow-up period of 2.23 years (range = 1.23-4.25 years). For non–chronic cough patients, the median number of encounters was 39 (range = 18-78) over a median follow-up period of 7.70 years (range = 5.04-10.98 years).

In the first year after diagnosis, OCCS prescriptions represented 71% of 18,343 antitussive orders for chronic cough patients; 21% of chronic cough patients received OCCS (vs 7% of non–chronic cough patients); and the number of OCCS prescriptions per 100 patients was 56 for chronic cough (total of 15,274) versus 14 for non–chronic cough.

The median time between first and last OCCS prescription was longer for chronic cough patients (175 days vs 125 days, P<.001).

Multivariable analysis revealed:

• Chronic cough patients: odds ratio [OR] of 2.0 for receiving OCCS (95% CI = 1.88-2.08)
• Non-White patients: OR = 1.4 (95% CI = 1.32-1.45)
• Urban residents: OR = 1.2 (95% CI = 1.16-1.31)
• Medicaid insurance: OR = 2.8 (95% CI = 2.62-2.91)
• Self-pay: OR = 1.4 (95% CI = 1.25-1.46).

Frequency of OCCS prescriptions was higher for chronic cough patients (1.8 times more frequent than non–chronic cough patients), Medicare recipients (1.2 times more frequent), Medicaid recipients (1.6 times more frequent), and self-pay patients (1.3 times more).

Commonly prescribed drugs included acetaminophen/hydrocodone (34% of prescriptions), fentanyl (18%), morphine (9.8%), tramadol (4.2%), codeine/guaifenesin (4.1%), and acetaminophen/oxycodone (3.2%). Thirty-one percent of chronic cough prescriptions contained hydrocodone, with 6.5% of these also containing a decongestant, expectorant, or antihistamine.

OCCS drugs were ordered for 38% of chronic cough patients with Medicaid, 18% with Medicare, and 15% with commercial insurance. The study observed a longitudinal increase in OCCS prescribing over the study period. Age was associated with a slight increase in OCCS prescriptions (OR = 1.02 per year, 95% CI = 1.01-1.03). Female gender was associated with a small increase in OCCS prescriptions (OR = 1.05, 95% CI = 1.01-1.09).

The study had limitations inherent to retrospective designs, including potential selection bias and incomplete data capture. The researchers noted that more recent data might show different results, and the study did not assess the appropriateness of prescriptions or their specific indications.

The study authors concluded, "In summary, in a cohort of 23,210 patients with chronic cough, about one in five patients with chronic cough received an OCCS prescription, and the odds of an OCCS prescription were twice as great in [patients with] chronic cough as compared to [those with] non–chronic cough.... In the face of an ongoing opioid crisis, the magnitude of OCCS prescriptions underscores the need for more effective non-opioid drugs to treat chronic cough, and more effective implementation of diagnostic strategies to determine a cough’s cause."

Disclosures can be found in the study.