- Email: [email protected]
Reply by Drs. Russell and Anderson
March I, 1963 Am. J, Obst. & Gynec.
700 Correspondence
trol period are far from approaching statistical significance, since probabilities based on x2 are more than 50 out of 100 that the obtained differences might have resulted from chance alone. It is also noteworthy that during 1958 chloramphenicol was widely used for "prophylactic" treatment of infants born to mothers with prolonged rupture of fetal membranes (Kent, S. P .. and Wideman, G. L., J. A. M. A. 171: 1199, 1959; Lischner, H., et al.. J. Pcdiat. 59: 21, 1961; Sutherland, J. M., A. M. A. J. Dis. Child. 97: 761, 1959). Chloramphenicol was used at the Los Angeles County Hospital quite commonly during 1958 as "prophylaxis" for premature infants, following prolonged rupture of membranes, and evaluated there by means of a controlled study between March, 1958, and February, 1959 (Burns, L. E., et a!., New England J. Med. 261: 1318, 1959). Consequently, the important variable of chloramphenical toxicity associated with neonatal deaths was present during the first time period of January, 1958, through June, 1959, studied by Russell and Anderson. This latter error in study design could have been avoided by using alternating cases instead of a consecutive control period following tlw experimental period. Miriam G. Wilson, M.D. Assistant Professor of Pediatrics University of California Medical Center Los Angeles 24, California
Oct. 11, 1962
Reply by Drs. Russell and Anderson To the Editors: We appreciate the opportunity of reviewing Dr. Miriam Wilson's letter and note with interest her observations regarding the statistical validity of the data presented. It is quite true that based solely on the X~ test, 4 maternal deaths might have "resulted from chance alone" in the first period without regard to the clinical condition existing. However, it has been clinically apparent to us on repeated occasions that the patient who is allowed to develop amnionitis as a consequence of ruptured membranes does much more poorly
than her sister who is delivered soon after this complication as regards the outcome for both patient and offspring. That early delivery is becoming a general trend in treatment iu mosr Lcnters when the patient is over 35 weeks pregnant would seem to offer some justification for this course of management. If one refers to the outcome in those infants over 2,500 grams in weight, where the added factor of prematurity is not operative, the perinatal deaths number 10 in the first group (with amnionitis) as compared to 2 in period II. Of the 10 notru, 9 were stillbirths, in which no factor of chloramphenicol toxicity could possibly be an "important vztriable," since these infants obviously could not have rrceivcd such medication. This paper was intended to be a clinic a1 one, presenting the data based on clinical obserYations in a highly heterogenous group of indigent patients. Many variables could not be completely assessed or weighed, as regards their statistical significance. However, we must disagree with Dr. Wilson's statement that the data "do not support their conclusions that the so-called aggressive managemrnt is advantageous to mother and baby." Additional observations in individual cases since the preparation of the paper have· further confirmed our beliefs that prolonged rupture of the membranes in this group of patit:nts is a complication with definite. potmtially 1.-thal, hazards to mother and baby, and the risk of infection is great. We quite agree that m..llly ob'<:rvations in the management of individwd complications cannot stand the scrutiny of dte X~; however, clinical judgment cannot all\ avs be based on rigid mathematical formulas. \V e are again reminded that our aeronautical engineer friends continue to assure us that it is aerodynamically impossible for the bumblebee to fly with the wing construction he possesses, based on all known mathematical principles. Keith P. Russell, M.D. Gail V. Anderson, M.D. 511 S. Bonnie Brae St. Los Angel11s 57, California
Dec. 12, 1962
700 Correspondence
trol period are far from approaching statistical significance, since probabilities based on x2 are more than 50 out of 100 that the obtained differences might have resulted from chance alone. It is also noteworthy that during 1958 chloramphenicol was widely used for "prophylactic" treatment of infants born to mothers with prolonged rupture of fetal membranes (Kent, S. P .. and Wideman, G. L., J. A. M. A. 171: 1199, 1959; Lischner, H., et al.. J. Pcdiat. 59: 21, 1961; Sutherland, J. M., A. M. A. J. Dis. Child. 97: 761, 1959). Chloramphenicol was used at the Los Angeles County Hospital quite commonly during 1958 as "prophylaxis" for premature infants, following prolonged rupture of membranes, and evaluated there by means of a controlled study between March, 1958, and February, 1959 (Burns, L. E., et a!., New England J. Med. 261: 1318, 1959). Consequently, the important variable of chloramphenical toxicity associated with neonatal deaths was present during the first time period of January, 1958, through June, 1959, studied by Russell and Anderson. This latter error in study design could have been avoided by using alternating cases instead of a consecutive control period following tlw experimental period. Miriam G. Wilson, M.D. Assistant Professor of Pediatrics University of California Medical Center Los Angeles 24, California
Oct. 11, 1962
Reply by Drs. Russell and Anderson To the Editors: We appreciate the opportunity of reviewing Dr. Miriam Wilson's letter and note with interest her observations regarding the statistical validity of the data presented. It is quite true that based solely on the X~ test, 4 maternal deaths might have "resulted from chance alone" in the first period without regard to the clinical condition existing. However, it has been clinically apparent to us on repeated occasions that the patient who is allowed to develop amnionitis as a consequence of ruptured membranes does much more poorly
than her sister who is delivered soon after this complication as regards the outcome for both patient and offspring. That early delivery is becoming a general trend in treatment iu mosr Lcnters when the patient is over 35 weeks pregnant would seem to offer some justification for this course of management. If one refers to the outcome in those infants over 2,500 grams in weight, where the added factor of prematurity is not operative, the perinatal deaths number 10 in the first group (with amnionitis) as compared to 2 in period II. Of the 10 notru, 9 were stillbirths, in which no factor of chloramphenicol toxicity could possibly be an "important vztriable," since these infants obviously could not have rrceivcd such medication. This paper was intended to be a clinic a1 one, presenting the data based on clinical obserYations in a highly heterogenous group of indigent patients. Many variables could not be completely assessed or weighed, as regards their statistical significance. However, we must disagree with Dr. Wilson's statement that the data "do not support their conclusions that the so-called aggressive managemrnt is advantageous to mother and baby." Additional observations in individual cases since the preparation of the paper have· further confirmed our beliefs that prolonged rupture of the membranes in this group of patit:nts is a complication with definite. potmtially 1.-thal, hazards to mother and baby, and the risk of infection is great. We quite agree that m..llly ob'<:rvations in the management of individwd complications cannot stand the scrutiny of dte X~; however, clinical judgment cannot all\ avs be based on rigid mathematical formulas. \V e are again reminded that our aeronautical engineer friends continue to assure us that it is aerodynamically impossible for the bumblebee to fly with the wing construction he possesses, based on all known mathematical principles. Keith P. Russell, M.D. Gail V. Anderson, M.D. 511 S. Bonnie Brae St. Los Angel11s 57, California
Dec. 12, 1962