{
  "schema_version": 1,
  "id": "grayscale-screen-time-friction-boundary-2026",
  "canonical_url": "https://brali-lifeos.github.io/evidence/grayscale-screen-time-friction-boundary-2026/",
  "json_url": "https://brali-lifeos.github.io/evidence/grayscale-screen-time-friction-boundary-2026/index.json",
  "decision": "propose-protocol",
  "decision_label": "Protocol candidate",
  "reviewed_at": "2026-09-11",
  "reviewed_by": "Brali Evidence Reviewer",
  "source": {
    "title": "A cross-over feasibility trial of smartphone grayscale mode in medical students",
    "url": "https://www.frontiersin.org/journals/digital-health/articles/10.3389/fdgth.2026.1816095/full",
    "type": "primary-study",
    "doi": "10.3389/fdgth.2026.1816095",
    "citation_text": "Hagerty J, Saretha S, Phung B, et al. Front Digit Health. 2026;8:1816095.",
    "study_design": "Two-week cross-over feasibility trial with consecutive one-week grayscale and color conditions. Assignment used a balanced alternating sequence based on enrollment order; participants served as their own controls. Mixed-effects models analyzed repeated daily screen-time observations.",
    "population": "First-year medical students at one US allopathic medical school. Sixty-one enrolled and 51 completed both study phases.",
    "intervention_or_exposure": "Smartphone display set to grayscale for one week versus normal color for one week. Participants transcribed daily screen-time values from their device's built-in tracking feature and completed exploratory end-of-week surveys.",
    "outcomes": [
      "Daily smartphone screen time",
      "Exploratory self-reported productivity",
      "Exploratory self-reported sleep quality",
      "Feasibility and qualitative usability feedback"
    ]
  },
  "supported_claim": "For a person who already wants to reduce habitual smartphone use, grayscale is a reasonable low-cost, reversible experiment. In this small short cross-over trial, grayscale was associated with about 28 fewer minutes of daily phone screen time on average. The result supports a screen-time-friction protocol, not a productivity, sleep, mental-health, or durable behavior-change claim.",
  "unsupported_or_overstated_claims": [
    "Grayscale reliably improves productivity or sleep.",
    "Grayscale treats problematic smartphone use or mental-health conditions.",
    "Everyone will reduce phone use by about 28 minutes per day.",
    "One week is an optimal or necessary duration.",
    "Lower phone screen time necessarily means less total digital distraction rather than substitution to another device."
  ],
  "limitations": [
    "Small single-school sample of first-year medical students.",
    "Short two-week study with one week per condition and no washout period.",
    "Participants and investigators could not blind the visible display condition.",
    "Screen-time values were participant-reported from built-in device trackers without screenshot verification.",
    "Exploratory productivity and sleep measures were non-validated and not powered for formal inference.",
    "Qualitative comments described color-dependent usability problems and substitution to other devices."
  ],
  "target_hack_ids": [
    "grayscale-phone-friction"
  ],
  "target_protocol_ids": [
    "brali:grayscale-phone-friction"
  ],
  "risk_flags": [],
  "notes": "Publish as a reversible interface nudge. Track the actual target behavior and substitution, allow color for functional tasks, and do not use broad digital-detox language."
}