The epidemiology of hereditary spastic paraplegia and associated common mental health outcomes in England and Northern Ireland

Abstract

Background: Hereditary Spastic Paraplegia (HSP) is a rare genetic neurological disorder that causes progressive spasticity and weakness in the lower limbs. This study aims to describe the prevalence and incidence of HSP and examine common mental health outcomes (depression and anxiety) in HSP patients in England and Northern Ireland. Methods: This retrospective cohort study used CPRD Aurum primary care data from 1 January 2000 to 31 December 2021. Annual cross-sectional and cohort studies were conducted for yearly prevalence and incidence of HSP. Common mental health outcomes were examined with a 1:4 matched cohort (age+/−1 year, sex, general practice). Descriptive analysis and logistic regression assessed the characteristics of the HSP cohort and baseline depression and anxiety. Cox regression assessed the hazard of new diagnosis of depression and anxiety. Results: The overall cohort included 31,302,579 patients; the matched cohort included 1455 HSP patients and 5726 control non-HSP patients. Patients who were male (adjusted odds ratio [aOR] 1.45, 95% CI: 1.31–1.61), of White ethnicity (lower odds in all other ethnicity) and from most other geographical areas compared to London had higher odds of a HSP diagnosis, with the highest odds for North East (aOR 3.51, 95% CI: 2.73–4.50) and Northern Ireland (aOR 3.15, 95% CI: 1.62–6.16). HSP prevalence increased from 2.83 per 100,000 population (95% CI: 2.49–3.20) in 2000 to 6.27 per 100,000 population (95% CI: 5.83–6.73) in 2021. HSP incidence remained stable from 0.12 per 100,000 person-years (95% CI: 0.06–0.22) in 2000 to 0.29 per 100,000 person-years (95% CI: 0.20–0.40) in 2021. HSP patients had higher odds of baseline pre-existing depression (aOR: 1.74, 95% CI: 1.47–2.06) and anxiety (aOR: 1.31, 95% CI: 1.08–1.60); and higher hazard for new diagnosis of depression (adjusted hazard ratio [aHR]: 1.57, 95% CI: 1.26–1.96) and anxiety (aHR: 1.41, 95% CI: 1.12–1.76). Conclusion: This first descriptive epidemiological study for HSP in England and Northern Ireland, demonstrated the utility of primary care routine health records for studying rare diseases. The higher rates of common mental health conditions in HSP patients illustrated the importance of access to mental health support.