A 'reserved for you' influenza-vaccine text,
does it really help with Increased same-day influenza vaccination versus usual care without a study text?
research showsThe grade is C with 50 points. The trial randomized 11,188 patients across three arms and analyzed 10,158 whose appointments remained eligible. Same-day vaccination was 1,168/3,375 (34.61%) with reserved wording, 1,113/3,351 (33.21%) with availability wording, and 1,075/3,432 (31.32%) with no study text. Reserved wording beat no text by 3.3 points (P=.004), but the 1.4-point contrast with availability wording was null (P=.31). This was a small process-outcome effect, not a clinical disease outcome.
ads claimA reminder effect is not the vaccine's efficacy against infection or hospitalization. Verdict 2558 is B with 72 points for the vaccine itself in a different intervention and outcome; this verdict assesses a behavioral message.
Useful facts when choosing a product
- Three texts with reserved wording and a vaccine-vial image were sent the day before the visit.
- Reserved wording was +3.3 points versus no text but a nonsignificant +1.4 points versus availability wording.
- Verdict 2558 is B with 72 points for high-dose vaccine itself, a different intervention and endpoint.
Chamgap Semantic Classification Code
Candidate index · review held
M.three-preappointment-influenza-vaccine-texts-saying-a-dose-was-reserved.UNK.same-day-influenza-vaccination.increase.usual-careMedicinal interventions > Three preappointment influenza-vaccine texts saying a dose was reserved > Unknown > same-day influenza vaccination > Increase claim > Usual care
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
The 2022 three-arm randomized trial by Buttenheim A, Milkman KL, Duckworth AL, Gromet DM, Patel M, and Chapman G allocated 11,188 patients to reserved wording, availability wording, or no study text. After appointment cancellations and changes, 10,158 entered the primary analysis. The NCT04565353 outcome was influenza vaccination on the scheduled visit date. Reserved versus no text was +3.3 points, P=.004; reserved versus available was +1.4 points, P=.31. Support came from NIA/NIH P30AG034532, the Gates Foundation, Flu Lab, Penn Center for Precision Medicine Accelerator, the AKO Foundation, and individual donors; funders were reported to have no role in design or analysis.
Why this is classified as C (50)
A large publicly and philanthropically funded trial found a small process-outcome increase, but excluded some participants after randomization and found no added benefit from ownership wording, giving C with 50 points.
Counterpoint. Contact accuracy, consent rules, appointment access, and vaccine supply may change the absolute effect in another health system.
Rejudgment record. Cross-check applied — Cross-checked three-arm randomization and analysis counts, same-day vaccination rates, both prespecified contrasts and P values, funding, and disclosures against the original article
| Endpoint | S | Surrogate marker - laboratory or imaging measures |
| Replication | R1 | Single confirmatory trial |
| Independence | I2 | Decisive evidence is publicly or non-profit funded |
| Effect size | E~ | Statistically positive but below the threshold |
Stored derived and displayed grades match; this is not a current recalculation or validity check (C).
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Higher same-day vaccination with reserved texts versus no text | C | The absolute difference was +3.3 points, P=.004. |
| Added effect of reserved wording versus availability wording | D | The +1.4-point contrast was null, P=.31. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Buttenheim A, Milkman KL, Duckworth AL, Gromet DM, Patel M, Chapman G. 2022 | Three-arm randomized clinical trial | 11,188 randomized; 10,158 in the primary analysis | NIA/NIH P30AG034532, Gates Foundation, Flu Lab, Penn Center for Precision Medicine Accelerator, AKO Foundation, and individual donors | Receipt of influenza vaccine on the scheduled appointment date | 34.61% versus 33.21% versus 31.32%; reserved versus no text +3.3 points, P=.004; reserved versus available +1.4 points, P=.31 | Small process-outcome effect in a large independent trial |
Receipt — 1 References
All 1 cited sources were verified for existence at the original page (as of 2026-08-15).
Final verification and publication gate: Codex · Evidence date: 2026-08-15 · Corrections: none
Cite this verdict
[Chamgap] A 'reserved for you' influenza-vaccine text x same-day vaccination — Evidence Grade C·50. 1 cited sources checked. Source: https://chamgap.com/en/verdicts/immunity/reserved-influenza-vaccine-text-same-day-vaccination/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.