Burden of pneumococcal disease among adults with cerebral palsy

People with cerebral palsy (CP) may have an elevated risk of pneumococcal disease, which is a vaccine-preventable disease, but this has not been studied.

To compare the initial rate and number of incident pneumococcal disease events up to 9-years between adults with vs. without CP.

This retrospective cohort study accessed a 20 % random Fee-For-Service Medicare dataset from the Centers for Medicare and Medicaid Services, including claims from adults ≥18 years old with CP and elderly ≥65 years without CP from 01/01/2008-12/31/2019. The incidence rate (IR) per 1000 person-years, IR ratio (IRR), and the number distinct events of all-cause pneumonia, pneumococcal pneumonia, and invasive pneumococcal disease was estimated for each cohort up to 9-years of follow-up.

The IR and IRR of the first event was higher for adults with CP ≥ 18 years old compared to elderly without CP for all-cause pneumonia (IR[95 %CI] = 71.24[69.85-72.63] and 40.10[40.04-40.16], respectively; IRR[95 %CI] = 1.78[1.74-1.81]), pneumococcal pneumonia (IR[95 %CI] = 6.27[5.90-6.64] and 2.44[2.43-2.46], respectively; IRR[95 %CI] = 2.57[2.42-2.72]), and invasive pneumococcal disease (IR[95 %CI] = 0.64[0.52-0.75] and 0.26[0.26-0.27], respectively; IRR[95 %CI] = 2.44[2.04-2.93]). Among those with outcome events, adults ≥18 years old with CP had a higher number of distinct all-cause pneumonia (e.g., 0 and ≥ 7 events, 54.8 % and 1.7 % for men with CP and 71.9 % and 0.1 % for elderly men without CP) and pneumococcal pneumonia (e.g., 0 and ≥ 2 events, 96.1 % and 0.5 % for women with CP and 98.4 % and 0.1 % for elderly women without CP) events compared to elderly without CP. Notably, when stratified by sex and age group, the IR of pneumococcal pneumonia for both men and women with CP was comparable between the youngest age group, 18-25 years old, and elderly ≥75 years old without CP (e.g., 18-25 year old men with CP, IR[95 %CI] = 3.81[2.29-5.33] and ≥75 year old men without CP, 4.01[3.97-4.05]).

Findings suggest the at-risk window for pneumococcal disease begins about 4 decades earlier for CP compared to the general population; prevention efforts may need to consider implementing strategies earlier in the lifespan for this population.