{
  "generated_at": "2026-07-20T00:47:11.472Z",
  "evidence_grade": {
    "independent_pm25_association": "E1",
    "confounding_explanation": "E2"
  },
  "analysis_year": 2023,
  "complete_cases": 184,
  "year_selection_rule": "Latest year with at least 150 complete country observations across all pre-specified variables.",
  "sample_flow": [
    {
      "step": "World Bank economies excluding aggregates",
      "remaining": 217
    },
    {
      "step": "After requiring PM2.5 (µg/m³)",
      "remaining": 200
    },
    {
      "step": "After requiring Life expectancy (years)",
      "remaining": 200
    },
    {
      "step": "After requiring GDP per capita PPP",
      "remaining": 188
    },
    {
      "step": "After requiring Urban population (%)",
      "remaining": 188
    },
    {
      "step": "After requiring Population age 65+ (%)",
      "remaining": 188
    },
    {
      "step": "After requiring Health spending per capita PPP",
      "remaining": 184
    }
  ],
  "descriptive_statistics": {
    "PM2.5 (µg/m³)": {
      "n": 184,
      "mean": 22.23,
      "sd": 15.87,
      "min": 3.52,
      "p25": 11.13,
      "median": 18.14,
      "p75": 29.78,
      "max": 107.76
    },
    "Life expectancy (years)": {
      "n": 184,
      "mean": 73.09,
      "sd": 7.11,
      "min": 54.46,
      "p25": 67.34,
      "median": 73.6,
      "p75": 78.17,
      "max": 85.71
    },
    "GDP per capita PPP": {
      "n": 184,
      "mean": 25451.12,
      "sd": 25752.1,
      "min": 1033.01,
      "p25": 6250.43,
      "median": 16355.01,
      "p75": 38220.7,
      "max": 130296.84
    },
    "Urban population (%)": {
      "n": 184,
      "mean": 60.64,
      "sd": 22.14,
      "min": 15.06,
      "p25": 42.7,
      "median": 62.21,
      "p75": 78.78,
      "max": 100
    },
    "Population age 65+ (%)": {
      "n": 184,
      "mean": 9.6,
      "sd": 6.85,
      "min": 1.57,
      "p25": 3.65,
      "median": 6.76,
      "p75": 15.37,
      "max": 29.56
    },
    "Health spending per capita PPP": {
      "n": 184,
      "mean": 2064.43,
      "sd": 2444.33,
      "min": 28.26,
      "p25": 342.73,
      "median": 1110.73,
      "p75": 2923.38,
      "max": 13473.19
    }
  },
  "correlation_matrix": {
    "PM2.5 (µg/m³)": {
      "PM2.5 (µg/m³)": 1,
      "Life expectancy (years)": -0.256,
      "GDP per capita PPP": -0.174,
      "Urban population (%)": -0.074,
      "Population age 65+ (%)": -0.489,
      "Health spending per capita PPP": -0.366
    },
    "Life expectancy (years)": {
      "PM2.5 (µg/m³)": -0.256,
      "Life expectancy (years)": 1,
      "GDP per capita PPP": 0.754,
      "Urban population (%)": 0.588,
      "Population age 65+ (%)": 0.729,
      "Health spending per capita PPP": 0.721
    },
    "GDP per capita PPP": {
      "PM2.5 (µg/m³)": -0.174,
      "Life expectancy (years)": 0.754,
      "GDP per capita PPP": 1,
      "Urban population (%)": 0.598,
      "Population age 65+ (%)": 0.612,
      "Health spending per capita PPP": 0.862
    },
    "Urban population (%)": {
      "PM2.5 (µg/m³)": -0.074,
      "Life expectancy (years)": 0.588,
      "GDP per capita PPP": 0.598,
      "Urban population (%)": 1,
      "Population age 65+ (%)": 0.432,
      "Health spending per capita PPP": 0.576
    },
    "Population age 65+ (%)": {
      "PM2.5 (µg/m³)": -0.489,
      "Life expectancy (years)": 0.729,
      "GDP per capita PPP": 0.612,
      "Urban population (%)": 0.432,
      "Population age 65+ (%)": 1,
      "Health spending per capita PPP": 0.739
    },
    "Health spending per capita PPP": {
      "PM2.5 (µg/m³)": -0.366,
      "Life expectancy (years)": 0.721,
      "GDP per capita PPP": 0.862,
      "Urban population (%)": 0.576,
      "Population age 65+ (%)": 0.739,
      "Health spending per capita PPP": 1
    }
  },
  "variables": {
    "outcome": "Life expectancy at birth",
    "exposure": "PM2.5 mean annual exposure",
    "controls": [
      "Log GDP per capita PPP",
      "Urban population share",
      "Population age 65+ share",
      "Log health spending per capita PPP",
      "Region fixed effects"
    ]
  },
  "models": [
    {
      "id": "M0",
      "label": "Unadjusted",
      "n": 184,
      "degrees_freedom": 182,
      "rmse": 6.89,
      "r_squared": 0.066,
      "adjusted_r_squared": 0.061,
      "coefficients": {
        "Intercept": {
          "estimate": 75.6415,
          "robust_se": 1.2068,
          "test_statistic": 62.682,
          "p_value": 0,
          "ci95_low": 73.2763,
          "ci95_high": 78.0068
        },
        "PM2.5 per 10 µg/m³": {
          "estimate": -1.1475,
          "robust_se": 0.5619,
          "test_statistic": -2.042,
          "p_value": 0.0411,
          "ci95_low": -2.2488,
          "ci95_high": -0.0462
        }
      }
    },
    {
      "id": "M1",
      "label": "+ income",
      "n": 184,
      "degrees_freedom": 181,
      "rmse": 3.6,
      "r_squared": 0.746,
      "adjusted_r_squared": 0.744,
      "coefficients": {
        "Intercept": {
          "estimate": 23.0753,
          "robust_se": 2.2096,
          "test_statistic": 10.443,
          "p_value": 0,
          "ci95_low": 18.7445,
          "ci95_high": 27.406
        },
        "PM2.5 per 10 µg/m³": {
          "estimate": -0.1951,
          "robust_se": 0.2059,
          "test_statistic": -0.947,
          "p_value": 0.3434,
          "ci95_low": -0.5986,
          "ci95_high": 0.2085
        },
        "Log GDP per capita PPP": {
          "estimate": 5.2614,
          "robust_se": 0.2122,
          "test_statistic": 24.795,
          "p_value": 0,
          "ci95_low": 4.8455,
          "ci95_high": 5.6773
        }
      }
    },
    {
      "id": "M2",
      "label": "+ demography & urbanization",
      "n": 184,
      "degrees_freedom": 179,
      "rmse": 3.451,
      "r_squared": 0.77,
      "adjusted_r_squared": 0.764,
      "coefficients": {
        "Intercept": {
          "estimate": 30.0423,
          "robust_se": 3.0386,
          "test_statistic": 9.887,
          "p_value": 0,
          "ci95_low": 24.0867,
          "ci95_high": 35.9979
        },
        "PM2.5 per 10 µg/m³": {
          "estimate": 0.15,
          "robust_se": 0.2467,
          "test_statistic": 0.608,
          "p_value": 0.5432,
          "ci95_low": -0.3336,
          "ci95_high": 0.6336
        },
        "Log GDP per capita PPP": {
          "estimate": 4.12,
          "robust_se": 0.4185,
          "test_statistic": 9.844,
          "p_value": 0,
          "ci95_low": 3.2998,
          "ci95_high": 4.9403
        },
        "Urban population per 10 pp": {
          "estimate": 0.1252,
          "robust_se": 0.1869,
          "test_statistic": 0.67,
          "p_value": 0.503,
          "ci95_low": -0.2412,
          "ci95_high": 0.4916
        },
        "Age 65+ per 5 pp": {
          "estimate": 1.2764,
          "robust_se": 0.3142,
          "test_statistic": 4.062,
          "p_value": 0,
          "ci95_low": 0.6605,
          "ci95_high": 1.8922
        }
      }
    },
    {
      "id": "M3",
      "label": "+ health resources",
      "n": 184,
      "degrees_freedom": 178,
      "rmse": 3.439,
      "r_squared": 0.772,
      "adjusted_r_squared": 0.766,
      "coefficients": {
        "Intercept": {
          "estimate": 31.6527,
          "robust_se": 3.3112,
          "test_statistic": 9.559,
          "p_value": 0,
          "ci95_low": 25.1628,
          "ci95_high": 38.1425
        },
        "PM2.5 per 10 µg/m³": {
          "estimate": 0.2387,
          "robust_se": 0.2395,
          "test_statistic": 0.997,
          "p_value": 0.3188,
          "ci95_low": -0.2306,
          "ci95_high": 0.708
        },
        "Log GDP per capita PPP": {
          "estimate": 3.3275,
          "robust_se": 0.7276,
          "test_statistic": 4.573,
          "p_value": 0,
          "ci95_low": 1.9014,
          "ci95_high": 4.7536
        },
        "Urban population per 10 pp": {
          "estimate": 0.0459,
          "robust_se": 0.1931,
          "test_statistic": 0.238,
          "p_value": 0.8122,
          "ci95_low": -0.3327,
          "ci95_high": 0.4244
        },
        "Age 65+ per 5 pp": {
          "estimate": 1.1286,
          "robust_se": 0.3575,
          "test_statistic": 3.157,
          "p_value": 0.0016,
          "ci95_low": 0.428,
          "ci95_high": 1.8293
        },
        "Log health spending per capita PPP": {
          "estimate": 0.9534,
          "robust_se": 0.722,
          "test_statistic": 1.32,
          "p_value": 0.1867,
          "ci95_low": -0.4618,
          "ci95_high": 2.3686
        }
      }
    },
    {
      "id": "M4",
      "label": "+ region fixed effects",
      "n": 184,
      "degrees_freedom": 172,
      "rmse": 3.123,
      "r_squared": 0.819,
      "adjusted_r_squared": 0.807,
      "coefficients": {
        "Intercept": {
          "estimate": 39.096,
          "robust_se": 3.7211,
          "test_statistic": 10.506,
          "p_value": 0,
          "ci95_low": 31.8026,
          "ci95_high": 46.3894
        },
        "PM2.5 per 10 µg/m³": {
          "estimate": -0.0604,
          "robust_se": 0.2589,
          "test_statistic": -0.233,
          "p_value": 0.8155,
          "ci95_low": -0.5678,
          "ci95_high": 0.447
        },
        "Log GDP per capita PPP": {
          "estimate": 2.9126,
          "robust_se": 0.7064,
          "test_statistic": 4.123,
          "p_value": 0,
          "ci95_low": 1.5281,
          "ci95_high": 4.2971
        },
        "Urban population per 10 pp": {
          "estimate": 0.0545,
          "robust_se": 0.1936,
          "test_statistic": 0.281,
          "p_value": 0.7785,
          "ci95_low": -0.325,
          "ci95_high": 0.4339
        },
        "Age 65+ per 5 pp": {
          "estimate": 1.3681,
          "robust_se": 0.3668,
          "test_statistic": 3.73,
          "p_value": 0.0002,
          "ci95_low": 0.6492,
          "ci95_high": 2.0869
        },
        "Log health spending per capita PPP": {
          "estimate": 0.4878,
          "robust_se": 0.7065,
          "test_statistic": 0.69,
          "p_value": 0.4899,
          "ci95_low": -0.897,
          "ci95_high": 1.8725
        },
        "Region: Europe & Central Asia": {
          "estimate": -0.0693,
          "robust_se": 0.7667,
          "test_statistic": -0.09,
          "p_value": 0.928,
          "ci95_low": -1.5721,
          "ci95_high": 1.4335
        },
        "Region: Latin America & Caribbean ": {
          "estimate": 0.5125,
          "robust_se": 0.8184,
          "test_statistic": 0.626,
          "p_value": 0.5312,
          "ci95_low": -1.0915,
          "ci95_high": 2.1166
        },
        "Region: Middle East, North Africa, Afghanistan & Pakistan": {
          "estimate": 2.9962,
          "robust_se": 1.2277,
          "test_statistic": 2.44,
          "p_value": 0.0147,
          "ci95_low": 0.5898,
          "ci95_high": 5.4025
        },
        "Region: North America": {
          "estimate": -1.3253,
          "robust_se": 2.7881,
          "test_statistic": -0.475,
          "p_value": 0.6345,
          "ci95_low": -6.7899,
          "ci95_high": 4.1393
        },
        "Region: South Asia": {
          "estimate": 3.6975,
          "robust_se": 1.5215,
          "test_statistic": 2.43,
          "p_value": 0.0151,
          "ci95_low": 0.7154,
          "ci95_high": 6.6795
        },
        "Region: Sub-Saharan Africa ": {
          "estimate": -2.5033,
          "robust_se": 0.8962,
          "test_statistic": -2.793,
          "p_value": 0.0052,
          "ci95_low": -4.2598,
          "ci95_high": -0.7468
        }
      }
    }
  ],
  "pm25_effect": {
    "unadjusted_years_per_10ug_m3": {
      "estimate": -1.1475,
      "robust_se": 0.5619,
      "test_statistic": -2.042,
      "p_value": 0.0411,
      "ci95_low": -2.2488,
      "ci95_high": -0.0462
    },
    "fully_adjusted_years_per_10ug_m3": {
      "estimate": -0.0604,
      "robust_se": 0.2589,
      "test_statistic": -0.233,
      "p_value": 0.8155,
      "ci95_low": -0.5678,
      "ci95_high": 0.447
    },
    "absolute_attenuation_fraction": 0.947
  },
  "sensitivity": {
    "leave_one_region_out": [
      {
        "excluded_region": "East Asia & Pacific",
        "n": 155,
        "pm25_estimate": 0.2081
      },
      {
        "excluded_region": "Europe & Central Asia",
        "n": 135,
        "pm25_estimate": 0.3311
      },
      {
        "excluded_region": "Latin America & Caribbean ",
        "n": 153,
        "pm25_estimate": 0.1795
      },
      {
        "excluded_region": "Middle East, North Africa, Afghanistan & Pakistan",
        "n": 163,
        "pm25_estimate": -0.216
      },
      {
        "excluded_region": "North America",
        "n": 182,
        "pm25_estimate": 0.2381
      },
      {
        "excluded_region": "South Asia",
        "n": 178,
        "pm25_estimate": 0.1483
      },
      {
        "excluded_region": "Sub-Saharan Africa ",
        "n": 138,
        "pm25_estimate": 0.5946
      }
    ]
  },
  "ai_judgment": {
    "chinese": "在加入预先确定的经济、城市化、年龄结构、医疗投入和地区变量后，PM2.5 的估计效应衰减了约 95%，置信区间跨越零。总体负相关主要受到国家发展条件影响，当前不能确认 PM2.5 与预期寿命存在独立关联。",
    "status": "Adjusted association is inconclusive",
    "strongest_caution": "This remains a cross-sectional ecological model; residual confounding, measurement error and reverse pathways are possible.",
    "next_test": "Use repeated country-year data with country and year fixed effects, lags, and pre-specified sensitivity analyses."
  }
}