OBJECTIVE: The study aimed to evaluate the relationships between disease activity, functional capacity,  and  health-related  quality  of  life   (HRQoL) in   Filipino   patients   with   ankylosing   spondylitis (AS).
METHODS: Filipino AS patients gathered from the Rheumatology Clinic of the Philippine General Hospital (PGH) and from selected tertiary hospitals  in Metro Manila who have been  diagnosed  via  the  Revised New  York  Criteria  were  included.  Disease   activity  was measured using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), while functional capacity and HRQoL were measured using the Bath Ankylosing Spondylitis Functional  Index  (BASFI)  and Short Form (SF)-36, respectively.  Pearson's  correlation  was used to analyze  the  relationship  between  BASDAI and   BASFI,   and   between   BASDAI   and  SF-36.
RESULTS: Twenty-four patients entered the study.  Mean age was 38.75 ± 12.7  years  and  mean  age  at  diagnosis  was  31 ±  12.29  years.   Symptoms  occurred for  a   mean  of   9.0  ±   6.97  years  with  mean      duration of symptom onset to  diagnosis  of  3.38  ±  5.14  years.  Study subjects had mild to moderate disease activity. Functional  capacity  was most   impaired  in   performing a full day's activities at home or at work.  HRQoL  was highest in vitality and lowest in emotional role,  with  mental health components generally showing higher scores than physical health components. Pearson's correlation showed moderate positive correlation between BASDAI and BASFI (r=0.6016, p=0.0012) and moderate negative correlation between BASDAI  and  the  physical  health  domain  (r=  -0.6916,  p=0.0001)  and mental health domain (r= -0.3575, p=0.0863)  of SF-36. However, only the first two correlations were statistically  significant.
CONCLUSION: Filipino AS patients with higher disease activity have more functional disability and poorer physical  HRQoL.