Singapore loses more than SGD 2 billion every year due to asthma

Singapore spends more than SGD 2 billion (USD 1.5 billion) on asthma per year, almost all of which is due to incompletely controlled asthma, according to a recent study.

“These costs mainly come from presenteeism, as results reveal that those with asthma tend to come to work but perform below their potential due to their symptoms,” the researchers said. “[I]f all those with suboptimal control could be improved to well-controlled without cost, the total cost of asthma would be reduced by SGD 1.35 billion (USD 0.97 billion).”

Using a cross-sectional online survey, annual total and per-capita asthma costs were estimated in 300 adults and 221 children (through their parents). Questions included healthcare use, days of missed work, and productivity problems due to asthma. Analysis was stratified according to symptom control: uncontrolled, partly controlled, well-controlled.

Among adults, 38 percent each had partly and well-controlled asthma. While only 24 percent had uncontrolled condition, they nevertheless had the greatest related expenditures, spending a total of SGD 25,630 (USD 18,450) per year, as opposed to SGD 17,670 (USD 12,720) and SGD 5,230 (USD 3,770) in patients with partly and well-controlled asthma, respectively. [BMJ Open Respir Res 2021;doi:10.1136/bmjresp-2020-000654]

Absenteeism and presenteeism were much larger sources of asthma-related costs in adults. Among those with poorly controlled asthma, annual losses due to missing work or lower productivity at work were SGD 4,870 (USD 3,510) and SGD 17,610 (USD 12,680), respectively. For comparison, corresponding yearly values in patients with well-controlled asthma were SGD 430 (USD 310) and SGD 4,530 (USD 3,260).

On a population scale, taking into account overall asthma prevalence rates, a total of SGD 1.74 billion (USD 1.25 billion) are spent by adult asthma patients yearly. Forty-two percent of this amount come from those with uncontrolled asthma and 45 percent from the partly controlled group. Patients with well-controlled disease contribute only 13 percent of the total spending.

Similar trends were observed among children, such that per-capita spending was highest among those with uncontrolled disease. Healthcare-related costs were the major contributor to overall expenditure as opposed to absenteeism; there was no presenteeism measure among children.

Overall, SGD 0.35 billion (USD 0.25 billion) are spent on children with asthma per year in Singapore. Most of this is due to uncontrolled disease (SGD 0.22 billion; USD 0.16 billion), while partly controlled (SGD 0.09 billion; USD 0.06 billion) and well-controlled (SGD 0.03 billion; USD 0.02 billion) asthma have smaller contributions.

Aggregating the results for both groups, the researchers found that every year, asthma costs Singapore over SGD 2 billion (USD 1.5 billion). Patients with uncontrolled asthma account for 46 percent of this total expenditure, while only 13 percent come from those with well-controlled disease.

“A primary limitation is the potential for selection bias of the survey respondents. The survey relies on a convenience sample of asthma participants (and their parents) from an online panel and there is no way to determine whether those who chose to participate are representative of individuals with asthma in the broader community,” the researchers said, also pointing out that self-reports are prone to recall bias.

Nevertheless, “even if our figures are off by an order of magnitude, more precise estimates will not change the conclusion that asthma imposes a significant economic burden in Singapore and that the potential exists to reduce the burden through effective policies and treatments,” they added.