Four times a year the National Disease and Therapeutic Index (NDTI) requests from a representative sample of physicians in private practice records of patient visits during a 48-hour period. More than 1,500 physicians respond, and the data can be reliably projected on a national level. Also, the data can be compared validly year to year. The NDTI Review, published semiannually by Lea, Incorporated, Ambler, Pa, provides an excellent exposition of what is happening in medicine.
The June 1971 issue of NDTI Review discloses trends in venereal disease. Patients with a gonococcal infection accounted for more than half of all venereal disease visits during 1970, and the numbers of visits have increased by 59% since the early 1960s. Males accounted for 69% of patient visits, giving further indication that gonorrhea is often asymptomatic in females. Ninety-four percent of patient visits for gonorrhea were by people less than 40 years of age.