NORTON SCIENTIFIC-Norton: Donald Roberts, "Scientific Fraud", and DDT

In this piece Roger Bate, Donald Roberts and Richard Tren accuse the UN of "Scientific Fraud against DDT". Their Accusation is based on an Opinion paper byRoberts and Tren published in Research and Reports in Tropical Medicine. So let's look at their paper and see where the "Scientific Fraud" is.

Roberts and Tren's key argument is that reductions in malaria in the Americas were not the result of Global Environmental Facility interventions but were caused by increased use of antimalarial drugs. In their own words:

"However, their successes were not a result of the interventions we describe as components of the GEF project. Their successes were mostly a result of wide distributions of antimalarial drugs to suppress malaria (see Table 1). Data in the Table reveal trends of increased numbers of antimalarial pills distributed per diagnosed case and decreased numbers of cases. Equally obvious is the decreased numbers of pills distributed per diagnosed case, and increased numbers of cases in two countries (Costa Rica and Panama)."

So their argument rests on table 1. Here's table 1.

Country  pills/case  pills/case  % change in  % change             in 1990     in 2004   pills/case  in cases Mexico          235        2566         1092     -1307 Belize           21          82          390      -287 Costa Rica      653         100         -653       112 El Salvador      34       22802        67064     -8276 Guatemala        38          54          142      -144 Honduras         30          51          170      -338 Nicaragua       279        1319          473      -519 Panama          202         140         -144      1337 

The first thing that leaps out at you is that the table shows reductions of more than 100%, which is impossible. Panama cannot have experienced a decrease of 144% in pills/case. According to the two previous columns in the table there was a decrease from 202 to 140, which is a 31% reduction, not 144%. 202/140 is 144%, but it is not the case that the column contains the ratio of pill/case in 1990 divided by pills/case in 2004 (ie, is just labelled wrongly), because then the number for Guatemala would be 70%, not the 142% shown in the table. The column appears to show the bigger number divided by the smaller. That is, all the percent changes in that column are calculated incorrectly and the increases and decrease were calculated differently.