Recurrence of thyroid nodules after surgical removal in patients irradiated in childhood for benign conditions.

To determine the incidence of benign thyroid nodules and the risk factors for their recurrence after surgical removal, we followed 511 patients for 1 to 40.6 years (median, 11.2) after surgery for benign thyroid nodules arising after local irradiation for unrelated benign diseases in childhood. Recurrent thyroid nodules developed in 100 patients (19.5 percent). The risk of recurrence correlated inversely with the amount of thyroid tissue removed. Women had a higher recurrence rate than men (28.4 percent vs. 10.3 percent; P less than 0.05). Among the 299 patients who had been treated with thyroid hormone at the discretion of their physicians to suppress thyroid-stimulating hormone, 25 had recurrences (8.4 percent), as compared with 72 of 201 patients who did not receive thyroid hormone (35.8 percent) (hazard ratio taking into account the extent of surgery and the patient's sex, 2.5; 95 percent confidence interval, 1.5 to 4.1). Histologic analysis of the 73 tissue samples from patients with recurrences showed that 14 samples (19.2 percent) were malignant. Thyroid hormone treatment had no effect on the rate of thyroid cancer. We conclude that radiation-associated benign thyroid nodules have a high recurrence rate, similar to that reported among nonirradiated patients with benign thyroid nodules. We also conclude that treatment with thyroid hormone decreases the risk of benign recurrences, particularly in women, but not the risk of cancer.

Effects of mandating seatbelt use: a series of surveys on compliance in Michigan.

Although proper use of automobile seatbelts reduces risk of serious injury or death in traffic crashes by 30 to 50 percent, seatbelt use remains low. Recently, several States have passed laws requiring the use of seatbelts. Michigan implemented such a law July 1, 1985. Direct-observation surveys of a probability sample of motorists throughout the State were conducted before the law was passed, after passage but before implementation, immediately after the law took effect, and 5 months after implementation. The results showed a significant increase in the use of restraints from 19.8 percent before the law was passed to 58.4 percent immediately after it took effect. A restraint use survey conducted in December 1985, 5 months after implementation, measured the use of restraints at 43.0 percent. Despite that decline, belt use was 117 percent higher than the 19.8 percent measured before passage of the law mandating the use of seatbelts.