Most US neurologists prescribing multiple sclerosis drugs receive pharma industry payments

Nearly 80% of US neurologists prescribing drugs for multiple sclerosis (MS) received at least one pharma industry payment, with higher volume prescribers more likely to be beneficiaries, finds a 5 year analysis of Medicare database payments, published in the open access journal BMJ Open.

And those in receipt of these payments were more likely to prescribe that company's drugs, especially if the sums involved were larger, sustained, and recent, the findings indicate.

Because of the lifelong nature of MS, effective therapies are usually continued indefinitely unless a patient's clinical response changes, explain the researchers. And MS drug prescriptions are Medicare's largest neurological drug expense despite making up a relatively small portion of total claims, they add.

While previously published research indicates that industry payments are associated with increased prescribing of marketed products, none of these studies focused on a market as competitive as the MS drugs market, say the researchers. 

They therefore set out to characterise industry payments to neurologists prescribing MS drugs and find out if the receipt of such payments might be associated with the likelihood of the preferential prescribing of that company's drugs.

They used publicly available data on payments made by pharma companies to doctors from the Centers for Medicare & Medicaid (CMS) Open Payments platform from 2015 to 2019.

Payments are classified as: research payments; ownership and investment interests; and general payments. The researchers focused on general payments to neurologists, linking these to Medicare Part D data, which covers prescription drugs, using National Provider Identification numbers and drug names. 

Their analysis included 7401 neurologists who had prescribed disease modifying therapies (DMTs) for at least 1 year, issuing a minimum of 11 prescriptions, and 20 DMTs manufactured by 10 companies.

In all, 5809 (78.5%) neurologists received 626,290 distinct industry payments from at least one drug company, totalling US$163.6 million between 2015 and 2019; 4999 (67.5%) neurologists received payments from two or more companies.

The average individual amount received was US$779, but 10% of recipients amassed US$155.7 million between them-95% of the total sums received–which suggests that drug companies may selectively target high-volume prescribers, say the researchers.

Higher prescription volumes were associated with a greater likelihood of receiving any payment type, particularly for consulting services, non-consulting services, such as speaking at an event, and travel/accommodation; the highest number of discrete payments was made for food and drink. 

The amount received was positively associated with prescription volume. Compared with those who received no payments from a company, those who did, were 13% more likely to prescribe that company's drugs.

The strongest association between industry payment and prescribing tendencies was observed for non-consulting services. These neurologists were 53% more likely to prescribe that company's drugs. 

Larger payments were also associated with a greater likelihood of preferential prescribing, rising in tandem with the size of the payment received: US$50 was associated with a 10% greater likelihood of prescribing that company's drugs; US$500 with a 26% greater likelihood; US$1000 with a 29% greater likelihood; and US$5000 with a 50% greater likelihood.

Longer duration of payments was another seemingly influential factor, ranging from a 12% greater likelihood of prescribing that company's drugs for one year of payments to 78% greater likelihood for 5 consecutive years. 

The recency of payments also seemed to be influential. A payment made 4 years earlier was associated with a 3% greater likelihood of prescribing that company's drugs, but a 34% greater likelihood when made in the same year.

This is an observational study, and as such, no firm conclusions can be drawn about cause and effect. And the researchers acknowledge that their study was limited to the prescribing of Part D drugs, and couldn't establish the appropriateness of prescribing, nor for which patients more expensive brand-name drugs were most suitable. 

A doctor's decision to prescribe is informed by many different factors, including national guidelines and/or institutional protocols, insurance cover, and patient preferences. These drivers are difficult to assess using publicly available data, but should be considered when interpreting the findings, emphasise the researchers.

Nevertheless their "findings raise concerns about excess pharmaceutical promotion efforts and their implications for physician prescribing for patients," they suggest.

"Promotional efforts to influence prescribing are especially concerning given the drugs' substantial costs, particularly if more expensive brand-name drugs are being prescribed instead of appropriate, effective, generically available alternatives," they point out.

"The Physician Payments Sunshine Act, which led to the creation of the Open Payments Database, was an important step forward in making transparent the financial conflicts of interest among physicians receiving industry payments.

"However, it remains unclear whether increased transparency has mitigated these conflicts of interest and their impact on prescribing behaviour, or simply given the public greater insight into the large scale of industry payments made to prescribers," they conclude.