Pfizer Australia Pty Ltd.

Osteoarthritis (OA) affects 10% of adults in the UK. Despite over one-third of people with OA experiencing chronic pain, few studies have examined the population-level impact of chronic pain associated with OA. We compared resource-use and epidemiological outcomes in patients with mild, moderate and severe chronic OA-associated pain and matched controls without known OA.

Retrospective, longitudinal, observational cohort study (July 2008 to June 2019).

Electronic records extracted from Clinical Practice Research Datalink GOLD primary care linked to Hospital Episode Statistics (HES).

Patients (cases; n=23 016) aged ≥18 years with chronic OA-associated pain. Controls (n=23 016) without OA or chronic pain matched on age, sex, comorbidity burden, general practitioner practice and available HES data.

None.

Total healthcare resource use (HCRU), direct healthcare costs in 0–12, 12–24 and 24–36 months postindex. Secondary outcomes included incidence and prevalence of chronic OA-associated pain and pharmacological management.

HCRU was consistently greater in cases versus controls for all resource categories during preindex and postindex periods. Across follow-up periods, resource use was greatest in patients with severe pain. In the first 12 months postindexing, mean total costs incurred by cases were four times higher versus matched controls (£256 vs £62); costs were approximately twice as high in cases vs controls for months 12–24 (£166 vs £86) and 24–36 (£150 vs £81; all p<0.0001). The incidence of new cases of chronic pain associated with OA was 2.64 per 1000 person-years; the prevalence was 1.4%.

This study highlights the real-world cost of chronic pain associated with OA in cases versus matched controls. We included patients with mild, moderate and severe pain associated with OA, and showed HCRU in discrete 1-year time frames. The true economic burden of pain associated with OA is likely to be considerably higher when indirect costs are considered.

Despite the prevalence of osteoarthritis (OA) in England, few studies have examined the health economic impact of chronic pain associated with OA. The aim of this study was to compare outcomes in patients with moderate-to-severe chronic pain associated with OA and matched controls without known OA.

Retrospective, longitudinal, observational cohort study.

Electronic records extracted from the Clinical Practice Research Datalink GOLD primary care database linked to Hospital Episode Statistics (HES) data set.

Patients (cases; n=5931) ≥18 years and with existing diagnosis of OA and moderate-to-severe pain associated with their OA, and controls matched on age, sex, comorbidity burden, general practitioner (GP) practice and availability of HES data.

None.

Total healthcare resource use (HCRU) and direct healthcare costs during 0-6, 0-12, 0-24 and 0-36 months of follow-up. Secondary outcomes measures included pharmacological management and time to total joint replacement.

Patients with moderate-to-severe chronic pain associated with OA used significantly more healthcare services versus matched controls, reflected by higher HCRU and significantly higher direct costs. During the first 12 months' follow-up, cases had significantly more GP consultations, outpatient attendances, emergency department visits and inpatient stays than matched controls (all p<0.0001). Total mean costs incurred by cases during 0-12 months' follow-up were five times higher in cases versus controls (mean (SD): £4199 (£3966) vs £781 (£2073), respectively). Extensive cycling through pharmacological therapies was observed; among cases, 2040 (34.4%), 1340 (22.6%), 841 (14.2%), 459 (7.7%) and 706 (11.9%) received 1-5, 6-10, 11-15, 16-20 and >20 lines of therapy, respectively.

This wide-ranging, longitudinal, observational study of real-world primary and secondary care data demonstrates the impact of moderate-to-severe chronic pain associated with OA in patients compared with matched controls. Further studies are required to fully quantify the health economic burden of moderate-to-severe pain associated with OA.

Assess Staphylococcus aureus (S. aureus) colonization in healthy Australian adults receiving an investigational S. aureus 3-antigen vaccine (SA3Ag).

In this phase 1, double-blind, sponsor-unblinded study, participants were randomized to receive a single dose (1 of 3 dose levels) of SA3Ag or placebo and a booster dose or placebo at 6 months. S. aureus isolates from nasal, perineal, and oropharyngeal swabs before and through 12 months post-vaccination were identified.

Baseline S. aureus colonization prevalence was 30.6% (any site), with nasal carriage (27.0%) more common than oropharyngeal/perineal (3.2% each). Following initial vaccination (low-dose: 102; mid-dose: 101; high-dose: 101; placebo: 102) and booster (low-dose: 45; mid-dose: 44; high-dose: 27; placebo: 181), placebo and SA3Ag groups showed similar S. aureus carriage through 12 months. Most colonized participants (74.0%) were colonized by single spa types. Placebo and SA3Ag groups had similar persistence of colonization, with 19.6-30.7% due to single spa types. Acquisition was observed in mid- and high-dose recipients (∼20%) and low-dose and placebo recipients (∼12%). Vaccination resulted in substantial increases in antibodies to all 3 antigens, irrespective of carriage status.

Based on descriptive analyses of this small study, SA3Ag vaccination did not impact S. aureus acquisition or carriage. Carriage status did not impact antibody responses to SA3Ag.