X-Linked Hypophosphatemia (XLH) Life Course Analysis: A Retrospective Cross-Sectional Study

Study type

• Study topic:
  Disease /health condition

  Other
• Study topic, other:
  Disease/Epidemiology study
• Study type:
  Non-interventional study
• Scope of the study:
  Disease epidemiology
• Data collection methods:
  Primary data collection

Non-interventional study

• Non-interventional study design:
  Cross-sectional

Study drug and medical condition

• Medical condition to be studied:
  Hereditary hypophosphataemic rickets

Population studied

• Short description of the study population:
  Adults aged 18 to 65 years with a diagnosis of XLH supported by clinical and biochemical features consistent with the disease, and/or a confirmed PHEX mutation in the adult or a family member, were included. To be eligible, adults also needed to have skeletal pain, defined as a Brief Pain Inventory (BPI) worst pain score ≥ 4 in the last 24 hours prior to screening, attributed to XLH/osteomalacia
• Age groups:
  • Adults (18 to < 46 years)
  • Adults (46 to < 65 years)
  • Adults (65 to < 75 years)
  • Adults (75 to < 85 years)
  • Adults (85 years and over)
• Special population of interest:
  Other
• Special population of interest, other:
  Patients with X-Linked Hypophosphatemia
• Estimated number of subjects:
  336

Study design details

• Main study objective:
  The objective of this study is to undertake a life course analysis of XLH in adulthood (from 18 years old onwards) in order to gain an understanding of adult disease manifestations, reported healthcare resource use and patient reported quality over the XLH life course
• Outcomes:
  1. Adult manifestations of XLH (fractures and associated specific co-morbidities) 2. Healthcare resource use (according to recordings of analgesia and orthopaedic surgery) 3. Quality of life, according to patient reported outcomes
• Data analysis plan:
  A descriptive analysis will be conducted on the two patient populations. The number and percentage of different disease manifestations for patients with XLH in each age cohort (18-29, 30-39, 40-49, 50-59 and 60+years) will be calculated. Categorical data (e.g. yes/no responses) will be summarized for each study and age cohort using simple tables of counts and percentages and/or Forest plots which will include the associated 95% confidence interval, calculated using the Wilson method (Altman et al. 2000). Continuous data (e.g. age at diagnosis) will be summarized for each study and age cohort using tables of summary statistics and / or Box plots, which will show the mean, median and quartiles, as well as extreme observations. All analysis will be conducted in Statistical Analysis Software (SAS®).