Fig. 3From: Rational design of an essential diagnostics network to support Universal Health Coverage: a modeling analysisDiagnostics by category (A) and tier at which used (B). These categories do not take account of frequency of use, for example X-ray is used frequently for many different purposes, whereas some laboratory tests are used infrequently for a few specific purposes. Green bars in 3b represent laboratory tests that should be available at lower tiers but due to infrastructural limitations must rely on specimen transport from lower tiers to higher tiersBack to article page