Table 3. Sensitivity analysis of number of meningitis cases, deaths and sequelae averted correlated with introduction of IDSR: Paired-comparison of outbreaks before (1996–2002) and after (2003–2007) IDSR implementation:

Outcomes measures#	Including 1996 data†		Excluding 1996 data†
	Median¶	Average¶ *	Median¶	Average¶ *
	(25th percentile 75th percentile)	(minimum maximum)	(25th percentile 75th percentile)	(minimum maximum)
Total cumulative cases averted (per 100,000)	−48(58 −201)	−134(666 −4,769)	−27(80 −115)	−17(666 −877)
Total cumulative deaths averted (per 100,000)	−10(−1 −25)	−19(61 −250)	−8(1 −17)	−10(61 −102)
Total cumulative sequelae averted (per 100,000)	−15(18 −65)	−44(267 −2,092)	−8(25 −38)	−6(267 −375)

^†We compared health outcomes for each of the 105 outbreaks before IDSR with each of the 86 outbreaks after IDSR implementation. We then re-ran these paired comparisons excluding the 1996, before IDSR data.

^#Number of health outcomes averted was calculated using the following equation: Outcome _{outbreak X after IDSR} – Outcome _{outbreak Y before IDSR}, where X for outbreak after IDSR and Y for outbreak before IDSR.

We calculated the number of sequelae by assuming 20% of all meningitis illness-related survivors have neurological defects (see main text).

^¶Negative figure indicates reduction in cases, deaths, and sequelae per outbreak after IDSR implementation.

*These columns present the simple average, minimum and maximum of the differences in health outcomes between paired outbreaks.

Data Source: WHO Multi-Diseases Surveillance Center, Ouagadougou, Burkina Faso.