{
  "source_file": "examples/phones-and-teen-sleep.csv",
  "as_of_year": 2026,
  "count": 6,
  "years": {
    "from": 2017,
    "to": 2023
  },
  "participants": {
    "total": 6085,
    "median": 525,
    "sources_with_n": 6
  },
  "designs": {
    "cross-sectional or survey": 1,
    "randomized trial": 3,
    "qualitative": 1,
    "longitudinal or cohort": 1
  },
  "settings": {
    "United States": 4,
    "Sweden": 1,
    "Japan": 1
  },
  "themes": [
    {
      "theme": "sleep duration",
      "sources": [
        "Marsh et al. (2017)",
        "Duarte (2020)",
        "Patel et al. (2021)",
        "Nakamura et al. (2022)",
        "Byrne et al. (2023)"
      ],
      "directions": {
        "positive": 0,
        "negative": 4,
        "none": 1,
        "mixed": 0
      },
      "count": 5,
      "main_direction": "negative",
      "agreement_percent": 80,
      "status": "agree"
    },
    {
      "theme": "mood",
      "sources": [
        "Patel et al. (2021)",
        "Byrne et al. (2023)"
      ],
      "directions": {
        "positive": 0,
        "negative": 1,
        "none": 1,
        "mixed": 0
      },
      "count": 2,
      "main_direction": "negative",
      "agreement_percent": 50,
      "status": "lean"
    },
    {
      "theme": "sleep onset",
      "sources": [
        "Lindgren et al. (2019)",
        "Nakamura et al. (2022)"
      ],
      "directions": {
        "positive": 0,
        "negative": 1,
        "none": 1,
        "mixed": 0
      },
      "count": 2,
      "main_direction": "negative",
      "agreement_percent": 50,
      "status": "lean"
    },
    {
      "theme": "daytime tiredness",
      "sources": [
        "Marsh et al. (2017)"
      ],
      "directions": {
        "positive": 0,
        "negative": 1,
        "none": 0,
        "mixed": 0
      },
      "count": 1,
      "main_direction": "negative",
      "agreement_percent": 100,
      "status": "single source"
    },
    {
      "theme": "fear of missing out",
      "sources": [
        "Duarte (2020)"
      ],
      "directions": {
        "positive": 0,
        "negative": 1,
        "none": 0,
        "mixed": 0
      },
      "count": 1,
      "main_direction": "negative",
      "agreement_percent": 100,
      "status": "single source"
    },
    {
      "theme": "melatonin",
      "sources": [
        "Lindgren et al. (2019)"
      ],
      "directions": {
        "positive": 0,
        "negative": 1,
        "none": 0,
        "mixed": 0
      },
      "count": 1,
      "main_direction": "negative",
      "agreement_percent": 100,
      "status": "single source"
    }
  ],
  "agreements": [
    {
      "theme": "sleep duration",
      "direction": "negative",
      "sources": 5,
      "agreement_percent": 80
    }
  ],
  "not_settled": [
    {
      "theme": "mood",
      "directions": {
        "positive": 0,
        "negative": 1,
        "none": 1,
        "mixed": 0
      },
      "sources": 2
    },
    {
      "theme": "sleep onset",
      "directions": {
        "positive": 0,
        "negative": 1,
        "none": 1,
        "mixed": 0
      },
      "sources": 2
    }
  ],
  "gaps": [
    "Only one source looks at \"daytime tiredness\" (Marsh et al. (2017)).",
    "Only one source looks at \"fear of missing out\" (Duarte (2020)).",
    "Only one source looks at \"melatonin\" (Lindgren et al. (2019)).",
    "2 of 6 sources have fewer than 100 participants: Lindgren et al. (2019), Duarte (2020).",
    "4 of 6 sources come from one setting (United States); results may not apply elsewhere."
  ],
  "sources": [
    {
      "id": 1,
      "cite": "Marsh et al. (2017)",
      "authors": "Marsh, Okoye",
      "year": 2017,
      "title": "Bedtime phone use and sleep in secondary school students",
      "design": "cross-sectional survey",
      "n": 1840,
      "setting": "United States",
      "themes": [
        {
          "name": "sleep duration",
          "direction": "negative"
        },
        {
          "name": "daytime tiredness",
          "direction": "negative"
        }
      ],
      "finding": "Students using a phone in the hour before bed slept 34 minutes less on school nights.",
      "url": "https://journal.example/marsh2017",
      "design_group": "cross-sectional or survey"
    },
    {
      "id": 2,
      "cite": "Lindgren et al. (2019)",
      "authors": "Lindgren, Aalto, Berg",
      "year": 2019,
      "title": "Evening screen light and melatonin in adolescents",
      "design": "randomized trial (lab)",
      "n": 42,
      "setting": "Sweden",
      "themes": [
        {
          "name": "sleep onset",
          "direction": "negative"
        },
        {
          "name": "melatonin",
          "direction": "negative"
        }
      ],
      "finding": "Two hours of bright tablet use delayed melatonin by about 30 minutes compared with reading print.",
      "url": "https://journal.example/lindgren2019",
      "design_group": "randomized trial"
    },
    {
      "id": 3,
      "cite": "Duarte (2020)",
      "authors": "Duarte",
      "year": 2020,
      "title": "Teens talk about phones at night",
      "design": "qualitative interviews",
      "n": 28,
      "setting": "United States",
      "themes": [
        {
          "name": "fear of missing out",
          "direction": "negative"
        },
        {
          "name": "sleep duration",
          "direction": "negative"
        }
      ],
      "finding": "Teens described staying up to keep up with group chats and felt worse rested.",
      "url": "https://journal.example/duarte2020",
      "design_group": "qualitative"
    },
    {
      "id": 4,
      "cite": "Patel et al. (2021)",
      "authors": "Patel, Greene, Holt",
      "year": 2021,
      "title": "Phone use and sleep across three years of high school",
      "design": "longitudinal cohort",
      "n": 3125,
      "setting": "United States",
      "themes": [
        {
          "name": "sleep duration",
          "direction": "negative"
        },
        {
          "name": "mood",
          "direction": "none"
        }
      ],
      "finding": "Each extra hour of evening phone use predicted 9 fewer minutes of sleep a year later; no link to mood.",
      "url": "https://journal.example/patel2021",
      "design_group": "longitudinal or cohort"
    },
    {
      "id": 5,
      "cite": "Nakamura et al. (2022)",
      "authors": "Nakamura, Sato",
      "year": 2022,
      "title": "Night mode settings and adolescent sleep",
      "design": "randomized trial",
      "n": 190,
      "setting": "Japan",
      "themes": [
        {
          "name": "sleep onset",
          "direction": "none"
        },
        {
          "name": "sleep duration",
          "direction": "none"
        }
      ],
      "finding": "Turning on night mode did not change sleep onset or sleep length over 3 weeks.",
      "url": "https://journal.example/nakamura2022",
      "design_group": "randomized trial"
    },
    {
      "id": 6,
      "cite": "Byrne et al. (2023)",
      "authors": "Byrne, Castillo",
      "year": 2023,
      "title": "Phones out of the bedroom: a school program",
      "design": "cluster randomized trial",
      "n": 860,
      "setting": "United States",
      "themes": [
        {
          "name": "sleep duration",
          "direction": "negative"
        },
        {
          "name": "mood",
          "direction": "negative"
        }
      ],
      "finding": "Schools that asked families to keep phones out of bedrooms saw 21 more minutes of sleep and slightly better mood.",
      "url": "https://journal.example/byrne2023",
      "design_group": "randomized trial"
    }
  ]
}