Figure 1.
Sensitivity analysis based on increasing proportions of lumbar punctures (LP) performed in persons with suspected meningitis, who do not have meningitis (i.e. negative LP). As the proportion of negative LPs increase, the cost per diagnostic evaluation changes differently for each regimen. For the comprehensive strategy, where every test is performed, there is a direct 1:1 linear increase in costs per each meningitis diagnosis. For the minimalist and stepwise strategies, the diagnostic algorithms stop after the first two and three tests are negative, respectively. Thus as the proportion of normal LPs approach 50%, the additional cost per meningitis diagnosis is $2.78, $7.08, and $16.00 for the minimalist, stepwise, and comprehensive strategies over the base model.