Burden of disease in pediatric patients with hypophosphatasia: results from the HPP Impact Patient Survey and the HPP Outcomes Study Telephone interview

Table 1 Patient demographics and characteristics of survey respondents

Characteristic	Patients (n = 59)
Sex, n (%)
Male	30 (50.8)
Female	29 (49.2)
Mean height, cm (SD)
Male (n = 26)	106.5 (29.4)
Female (n = 27)	105.7 (35.1)
Mean height Z-score, (SD)^a
Male (n = 30)	−3.0 (3.5)
Female (n = 29)	−3.2 (2.3)
Age at survey, years
Mean (SD)	7.6 (5.1)
Range	0–17
Age at HPP symptom onset, years
Mean (SD)	0.8 (0.9)
Range	0–4
Duration of symptomatic disease, years
Mean (SD)	7.0 (5.0)
Range	0–16

^a Mean height Z-scores were calculated using the Centers for Disease Control and Prevention method; because the date of birth or exact age in months for each patient was unknown, reported ages in whole numbers were rounded to 0.5 years (e.g. ages of 2 to < 3 years were rounded to 2.5 years)
HPP hypophosphatasia, SD standard deviation

ISSN: 1750-1172