| Park Column office | Base ’25 | Office YTDΔ | Matched twin (non-PC) | Match gap | Twin YTDΔ | Diff-in-diff |
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| Cohort | Offices | YTD ’25 | YTD ’26 | YTD Δ | May ’25 | May ’26 | May Δ |
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On the FTE-correct metric — hygiene visits per hygienist per day — Park Column GP offices improved +1.9% YTD while comparable non-Park-Column offices slipped −0.6%: a +2.5pp raw edge. New in v2: pair each office with a same-level twin and the edge holds and widens to +4.5pp (+3.3pp FTE-weighted). The catch is unchanged — offices that used the column most did not improve more.
What the Park Column is meant to do. When an appointment isn’t confirmed ~24 hours out, the office moves it into a “park” column and backfills the freed slot — the goal is to stop losing hygiene chair time to broken appointments. If it works, a rollout office should get more completed hygiene visits out of each hygienist-day than an office without the column.
Why per-hygienist, and why a matched baseline. Dividing by office operating days inflates the instant an office adds a hygienist. The correct normalization — the one SGA East uses — is visits per hygienist-day: completed hygiene visits ÷ hygienist days worked. We compared the 47 Park Column GP offices against the non-PC West offices over the same periods, and now also office-by-office against a same-level twin so the structural level gap can’t carry the result.
What we found. Per hygienist-day, Park Column GP went 5.83 → 5.94 YTD (+1.9%) while the control went 7.93 → 7.88 (−0.6%) — a +2.5pp raw edge. The matched-pairs cut tightens and strengthens this to +4.5pp (mean office +3.9% vs mean twin −0.6%), FTE-weighted +3.3pp, with 30 of 47 offices beating their peer. But splitting the rollout offices by reporting intensity shows no dose-response: regular +1.2%, occasional +0.2%, dormant +5.4%, correlation −0.135.
How to read it honestly. The YTD edge is genuine and now survives level-matching — the strongest version of the “it worked” case the data supports. What it still can’t do is pin the gain on the column: usage doesn’t track improvement. Without CDT-level appointment data we can’t isolate the specific appointments the column recovered.
Bottom line. On the FTE-correct metric, Park Column offices edged a matched baseline by +4.5pp YTD — a more robust read than v1 — but the absent usage dose-response keeps it short of proof. The Focus Priority tab turns this into the next move: where to drive daily use and audit hygiene schedules.
| Office | ROD | Subs | May ’25 | May ’26 | May Δ | YTD ’25 | YTD ’26 | YTD Δ |
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| ROD | Offices | May ’25 | May ’26 | May Δ | YTD ’25 | YTD ’26 | YTD Δ |
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Did hygiene visits per day actually improve at the 56 SGA West offices that rolled out the Park Column — measured from the PBI, because the offices won’t keep the manual daily form (22% form compliance)? This is the SGA West parallel to the SGA East risk-score readout.
Hygiene Visits per Hygienist-Day = completed hygiene visits ÷ hygienist days worked, per office per period. Completed hygiene visits = [Completed Visits] where User Type = "HYG"; hygienist days worked = [Work Days] where User Type = "HYG" (the FTE denominator). Cohort numbers are volume-weighted (Σ visits ÷ Σ hygienist-days).
The standing weakness of the raw comparison was that the control runs a structurally higher level (~7.9 vs ~5.9 VpD), so the cohorts aren’t matched. For each of the 47 GP offices we pick its nearest non-Park-Column twin by absolute YTD’25 baseline (minimizing |office.vpd_YTD25 − control.vpd_YTD25|) from the 23 control offices with usable data, then compute a per-pair diff-in-difference (office.vpd_YTD_pct − twin.vpd_YTD_pct) and aggregate. Median match distance is < 0.1 VpD, so each office faces a genuinely same-level peer. Result: matched edge +4.5pp simple, +3.3pp FTE-weighted, 30/47 offices beating their twin. The control set carries no ROD field, so the optional same-ROD constraint could not be applied; matching is on level alone.
We regress each office’s YTD change on its form-submission count (usage proxy) across the 47 GP offices: OLS slope −0.20, intercept 6.1, Pearson r = −0.135. Tiers: Regular reporters (10+ subs, n=22), Occasional (1–9, n=14), Dormant (0, n=11). A real column effect should show most in heavy users; the slope is slightly negative instead.
Per GP office: 0.45·headroom + 0.40·momentum + 0.15·actionable, each min-max normalized across the 47, then multiplied by √(hygienist provider-days) so high-FTE offices weigh more without fully dominating. Headroom = control YTD’26 ceiling (7.9) − office YTD’26; momentum = −YTDΔ (decliners float up); actionable = 1 if subs < 10. The recommendation line is templated from each office’s own fields.
May 2026 vs May 2025, and YTD Jan–May 2026 vs 2025. Park Column went live Oct/Nov 2025. Gen4 / SGA West Power BI dataset, queried via Service Principal; the 56 live offices matched by practice name to the PBI location dimension.
Hygiene VpD moves for reasons beyond the Park Column (staffing, demand, schedule template). This shows whether throughput moved in the right direction — it is not a clean attribution of the column alone. Without CDT-level appointment data we can’t yet prove the office moved the right appointments.
All figures computed client-side from the same PBI aggregate bundle as v1 (no patient-level data). Public aggregates only.