BASDAI, BASMI, a flare log, and a clinician PDF — from the home tab.

The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) is six 0–10 visual analog scales, averaged. The six questions cover fatigue, axial pain, peripheral joint pain, enthesitis, severity of morning stiffness, and duration of morning stiffness. A score above 4 is conventionally the threshold for active disease. VerbaFit presents the questions as horizontal sliders, with the anchors (none / very severe) calibrated to the original Garrett et al. instrument (1994). The seven-day rolling average is the headline number; the per-day score is preserved in the history.

BASDAI is sensitive to mood and to the day of the week, so the trend view shows each day against the week around it. A single 6.2 after a run of 4s is drawn as what it is: one bad morning, not a new baseline.

The Bath Ankylosing Spondylitis Metrology Index (BASMI) measures spinal mobility with five tests: tragus-to-wall distance, lumbar flexion (modified Schober), cervical rotation, lumbar side flexion, and intermalleolar distance. VerbaFit guides four of them with on-screen instructions and manual entry, converts each to a 0–10 score, and averages them. Lumbar side flexion is hard to self-measure reliably, so we leave it to the clinic and label the result as a four-component score.

BASMI moves slowly. We recommend measuring weekly, not daily. A score that drops by 0.5 in a year is meaningful; a drop in a week is measurement noise.

"Med score" in VerbaFit is the proportion of prescribed doses you actually took, weighted by drug class. A biologic injection is weighted 5x; a daily NSAID is weighted 1x; a weekly oral DMARD is weighted 3x. The score is the weighted sum of taken doses over the weighted sum of prescribed doses, expressed as a percentage. The instrument is not validated; the construction is ours, and the app says so.

The biologics directory covers ten drugs: the TNF inhibitors adalimumab (Humira), etanercept (Enbrel), certolizumab (Cimzia), and golimumab (Simponi); the IL-17 inhibitors secukinumab (Cosentyx), ixekizumab (Taltz), and bimekizumab (Bimzelx); the JAK inhibitors upadacitinib (Rinvoq) and tofacitinib (Xeljanz); and vedolizumab (Entyvio), for people whose AS comes with inflammatory bowel disease. Each entry has its typical dosing interval, a US cash price range, and the manufacturer’s patient assistance program link and phone number.

A flare is logged as a discrete episode, separate from the daily BASDAI check-in: the date, a 1–5 severity, how long it lasted, what you think triggered it, optional photos, and notes. Keeping episodes apart from the daily score means a bad fortnight shows up as a cluster of events, not as a smear across the trend.

One tap generates a clinician report for the last 30 days: the flares, the BASDAI trend, your current medications, injection adherence, and your Mediterranean diet score, as a PDF you can hand over or send ahead of an appointment. VerbaFit does not predict flares. It makes sure the ones you had are written down.