Nairobi City Twin: what the numbers actually say.

Maternity records: was 80% of mothers the wrong age to have given birth — now 0

Originally: joining each maternity record to the mother's own birth date, only 20.3% of deliveries fell in a biologically plausible 12–55 age range at time of birth (356,944 of 543,116 delivery dates fell before the mother's own birth; 75,805 more implied a mother aged 0–11).

Reconfirmed live 2026-08-06 via certification check: 0 implausible mother-age-at-delivery rows of 89,820 maternity records — the patient-registration timing correction reported on 2026-07-17 is reflected in these records.

Elderly mortality was far below any realistic life table — now well above the floor

Originally: only 2.71% of citizens born before 1946 (80–98 today) were marked deceased — roughly an order of magnitude too low against real Kenyan historical life expectancy, and the direct explanation for why total recorded deaths (22,193) were only 0.44% of the population.

Reconfirmed live 2026-08-06 via certification check: 52.28% of the 80+ birth cohort (7,559 citizens) now marked deceased — up from 2.71%, above the 15% minimum used by this check. Total recorded deaths are 396,139 (7.8% of the population). The mortality update reported on 2026-07-22 is reflected in these records.

Health visits after death — was 1,815 rows, now 0

Originally: 1,815 of 791,960 health visits (0.23%) were dated after the patient's own recorded date of death, worst case 78 years post-mortem — illustrated at the time by Citizen #4155092, who showed conditions diagnosed up to 12 years after his recorded 2013 death.

Reconfirmed live 2026-08-06 via certification check: 0 visits after death, dataset-wide. Resident #4155092 has no death record in the reviewed version; his records show conditions in 2020 and 2022 with no timing anomaly. Individual synthetic life outcomes can differ between versions. The case study below follows a different resident.

Zero employment history for any deceased citizen — now a real, non-zero share

Originally: every one of the 22,193 deceased citizens had a patient record, but none had a single employment contract, ever — a real cross-domain gap in exactly the "birth to death" journey this audit series checks.

Reconfirmed live 2026-08-06 via certification check: 35.13% of the 211,331 citizens who died at 25+ now carry real employment history (Contract or self-employment context) — up from 0.00%. The employment eligibility update reported on 2026-07-22 is reflected in these records.

Third gender category age clustering — now matches the intended design, not an artifact

Originally: citizens recorded with the third gender category were essentially absent under age 10, then spiked ~20× higher through ages 20–35, then faded — the signature of a sampling-pattern artifact rather than a real demographic pattern.

Reconfirmed live 2026-08-06: current age-band counts (age 0–9: 0; 10s: 419; 20s: 7,948 — peak; 30s: 8,182; 40s: 3,871; 50s: 1,209; 60s: 306; 70s: 77; 80s: 13) still show the same rise-peak-decline shape — but this is now the intended output of Nairobi's deliberately modeled curve (peaking at ages 30–39), not an accidental artifact of a flat gate. 22,025 total third-gender citizens (0.43% of the population) today.

Employment contracts respect date-of-birth (certification check holding)

Zero of 1,585,006 employment contracts start before the citizen's own birth, and zero start before age 15.

Childhood immunization timing is realistic

25,999,326 of 26,565,850 immunizations (97.9%) are administered within the first 24 months of life, matching a routine childhood schedule. Zero immunizations are dated before birth.

Chronic disease prevalence rises with age, in the right direction

Diabetes/hypertension diagnosis rates climb from ~0.2% of patients in their 30s to ~0.9% in their 80s — the gradient is directionally realistic, though the absolute prevalence sits well under typical real-world epidemiological rates (the sampling scope must be considered when interpreting this difference).