Iglesias, Mexico, English, 1980(71)
Medical service of the company polled at random airline stewardesses at the time they applied for assistance of a variety of clinical problems, personnel using contraception or suffering from obvious general or gynaecological problems were excluded
Widholm, Finland, English, 1979(72)
Control series of case-control study with mean age 15.7 years from two school classes who underwent same examination; mean age at menarche 13 years-study done in 1967. In order to obtain a picture of the need for drugs for pain relief and absenteeism, this second similar study was done
% Calculated from responders; 3.2% consulted doctor; 9.3% absent from schools due to pain.