Total drug costs grew to $2 billion in 2021, rising steadily from $1.4 billion in 2017, according to Green Shield Canada’s annual drug trends report.

The report, which is based on claims reported by Green Shield Canada, found the number of claimants also increased from 1.9 million to 2.1 million over the same period. While the average claims per claimant was 14 in 2021, down slightly from 15 in 2020, the total drug cost per claim increased to $68, up from $64 in the previous year.

While specialty drugs made up fewer than one per cent of claims in 2021 — up four per cent from 2020 — the average cost per claim for specialty drugs was nearly 64-times higher than for their non-specialty counterparts.

Read: Claims paid out to support mental health up 75% since 2019: CLHIA

More than half (54 per cent) of total drug costs were associated with the top five per cent of claimants, while a third (32 per cent) was associated with the top one per cent of claimants.

In 2021, the top five per cent most expensive claimants cost 21-times more on average, compared to the remaining 95 per cent of the claimant population ($10,538 versus $466). These high-cost claimants had six-times more claims (77 claims versus 11) at an average cost per claim that was more than double that of the rest of the claimant population ($137 versus $43).

Plan members treating rheumatoid arthritis, Crohn’s disease, colitis and psoriasis represented the largest share of total drug cost in both the top one per cent and top five per cent of high-cost claimant groups (45 per cent and 30 per cent, respectively). Use of these medications grew by 10 per cent and made up 53 per cent of specialty products in 2021, reaching roughly $321 million.

Read: Fewer plan members making drug claims, but specialty medications increasing average eligible amounts: report

The percentage of claimants using medications to manage their anxiety and depression symptoms rose by eight per cent to 463,600 in 2021, representing 22 per cent of all claimants in 2021.

While generic drugs accounted for 65 per cent of all claims in 2021, more than 25,000 claimants used a specialty drug to treat their medical conditions. Specialty drug costs grew by nine per cent from 2020 to 2021 and were associated with $604 million in total drug costs. Biologics accounted for 66 per cent of specialty drug expenditures, while biosimilars accounted for just two per cent.

Total costs for claimants in the $1,000 to $1,999 cost interval grew by 19 per cent over the past five years. The report noted diabetes is a significant cost driver within this interval, accounting for 57 per cent of total drug cost growth in 2021. Similarly, there was a 29 per cent increase in claimants using obesity medications in 2021, while there were 100 claimants using cystic fibrosis treatments, up from 34 claimants in 2017.

Read: 2022 Drug Plan Trends Report: High-cost drugs, DEI shaping drug plans