Disclaimer

The engaged-population property in plain language

SNMS reaches people who use mobile phones and who are willing to take a survey by phone or web. This population skews toward higher household wealth, higher education, and younger ages than the Nigerian population as a whole. The site reports both the literal voice of who SNMS reached (unweighted) and what those voices imply about Nigeria as a whole after weighting (IPW-calibrated).

What inverse-probability weighting does, and does not, do

Weighting assigns each respondent a multiplier so the overall sample matches the national wealth distribution measured by the MIS 2021. Respondents in scarcer wealth quintiles get larger weights so their experiences count for more in any aggregate calculation. Weighting works well in quintiles with many respondents and works less well in quintiles with very few. The Site flags any value where the underlying cell size is below 25. Headline values are unweighted and describe the engaged population the survey reaches. For comparison with national surveys, the calibrated values and the per-indicator verdicts apply. Calibration reduces but does not remove this engaged-population selection. The full reasoning, including why no wealth reweighting removes the engaged-population selection, is set out in the methodology.

When SNMS is the right reference

Operational programme intelligence at quarterly cadence; LGA-level resolution where MIS clusters at the state level; cross-cycle trend tracking on indicators where the engaged population is a coherent population to track over time; signal-detection on new interventions (SMC, R21 vaccine, brand-confirmation cascade, PPMV channel mix) that MIS does not measure; research dissemination, methods development, and presentation for scientific feedback, including at conferences.

When SNMS is not the right reference

Statements of nationally representative biomedical malaria prevalence; official statistics for the National Population Commission, or official international statistical reporting such as the WHO World Malaria Report; any single-point estimate intended to support legal, regulatory, or fiscal allocation that requires probability-sample provenance.

Not medical or clinical advice

Nothing on this Site is intended as medical, clinical, or diagnostic advice. Individuals concerned about malaria infection or symptoms should consult a qualified healthcare provider.