The Times is to be commended for your four-part, comprehensive series on drug testing (Oct. 27, 28, 29 and 30). It sheds some light on the problems and will perhaps dispel some of the hysteria related to our current "war on drugs." You have emphasized that drug testing is no panacea.
As a pathologist and former laboratory director, I point out several issues not covered in the series.
Who has the responsibility for "selecting a good lab" as you recommend? Most medical directors do not have the background or training to visit a lab, ask the right questions, and analyze daily quality control data, calibration curve and proficiency-testing results.
More commonly the decision will be made by a personnel director who will deal with a marketing person of the laboratory. They will be given a tour of the lab loaded with awesome machines and scientific types in white coats. That is, it looks good.
State or interstate licensing is, by no means, an indication that a lab is "good," but only that minimum standards have been met.