- Email: [email protected]
Science, evidence, and the use of the word scientific
CORRESPONDENCE
teenage pregnancy) also need to be addressed. Deborah A Cohen, *Thomas A Farley Louisiana State University Health Science Campus, Department of Public Health and Preventive Medicine, New Orleans, LA, USA; and *Louisiana Office of Public Health, 325 Loyola, New Orleans, LA 70112, USA 1
2
Hicks D. Is there a case for school-based screening for sexually transmitted diseases? Lancet 2000; 355: 864. Burstein GR, Gaydos CA, Drener-West M, Howell MR, Zenilman JR, Quinn TC. Incident chlamydia trachomatis infections among inner-city adolescent females. JAMA 1998; 280: 521–26.
this subject is thus desirable since it relates to fundamental issues in medicine, and the meaning and use of science and evidence in general. The newer post-normal science of chaos can bridge the gap between evidence and reality,3 and also reduce the culture gap between scientists and others, which Brewin notes, Snow discussed 40 years ago. V S Rambihar Scarborough Hospital, 3050 Lawrence Ave E, Toronto M1P 2V5, Canada (e-mail: [email protected]) 1
Science, evidence, and the use of the word scientific Sir—Science keeps changing and Thurstan Brewin’s jab at the use of the word “scientific” (Feb 12, p 586)1 invites an even deeper exploration of science and its relation to our understanding of evidence and reality. Hippocrates (450 BC) sought natural explanations for observed phenomena, changing the world-view from divine intervention and supernatural causes, and creating a new Greek science.2 Newton imposed structure and predictability on the world as a clockwork universe leading to Classical Science (1600–1900). Modern Science (since 1900s) provided us with a probabilistic universe and ultimate reductionism, all the way from quarks to quasars. A postmodern science has developed since the 1980s, of deconstructionism, responding to the collapse of normal science. Normal science (before 2000) refers to a puzzle solving approach, with uncertainty managed and values unspoken. A post-normal (not postmodern) science has since appeared, emerging from the new science of nonlinear dynamics, which recognises irregularity, subjectivity, and uncertainty as intrinsic and fundamental.3–5 This new science is variously also called chaos, complexity, or nonlinear dynamics. Science or evidence lies in the eye of the beholder, changing with time, place, and circumstance. Science may mean absolute truth and validity to some, with a relentless pursuit of certainty, whereas others may accept the inevitability of uncertainty, and the contextual and thus subjective nature of reality. The nature of evidence could now be considered contextual and changing. Brewin describes this changing concept of evidence when he decries ignoring explanations for phenomena “that on later reflection are equally possible”, and when he advocates weighing lack of evidence partly on “how much effort has been made to find it”. More general education, discussion, and debate on
1730
2
3
4 5
Brewin T. Use of the word “scientific”. Lancet 2000; 355: 586. Rambihar VS. CHAOS: from Cos to cosmos: a new art, science and philosophy of medicine . . . and everything else. Toronto: Vashna Publications, 1996. Rambihar VS. A new chaos based medicine beyond 2000: the response to evidence. Toronto: Vashna Publications, 1999. Kernick DP. After postmodernism. Lancet 2000; 355: 149. Funtowicz S, Ravetz J. Science for the postnormal age. Futures 1993; 25: 739–55.
Should menstruation be optional for women? Sir—We assume that Sarah Thomas and Charlotte Ellertson’s provocative essay (March 11, p 922)1 advocating amenorrhoea as a choice for women, best achieved through continuous use of oral contraceptive pill is intended to stimulate debate. What surprises us is the single-minded promotion of oral contraceptives as the only means by which to achieve this goal. As the pill scare, which followed a letter from the UK Committee on Safety of Medicines (CSM) on Oct 18, 1995,2 showed, the combined oral contraceptive pill can engender fear and distrust in physicians and patients. We know that any potential reported increase in complication rates amongst pill users will have important adverse repercussions for those women who most require effective contraception. Thomas and Ellerston neglect to mention that there are potential complications in prescribing continuous oral contraception, and that the use of the pill in this capacity represents an unlicensed indication with inherent medicolegal risks for the prescriber.3 Data from conventional use of oral contraceptive pill support the safety of the drug. The risk of death per annum from the pill is 1/3 the risk of dying as a result of an accident in the home, and 1/6 the risk of dying as a result of pregnancy.3 However, the oral contraceptive pill has deleterious effects on lipid metabolism and vascular disease. The pill-free interval whilst
producing pseudo menstruation, might have important systemic implications for long-term safety. HDL-cholesterol suppression is reversed by the end of the pill-free interval,3 this effect would be eliminated amongst continuous users of the oral contraceptive pill. What are the alternative available methods to provide amenorrhoea as a lifestyle choice for women? The only method to guarantee amenorrhoea is hysterectomy, but if women are prepared to accept hypomenorrhoea, or light spotting, as a compromise there are safe, effective medical and less radical surgical options. The levonorgestrel-releasing intrauterine system (Mirena LNG-IUS, Schering Health, West Sussex, UK) is a contraceptive with an unlicensed indication for the treatment of menorrhagia, producing a significant decrease in menstrual blood loss in 97% of women at 1 year follow-up. This contraceptive is well tolerated, lasts for 3–5 years with minimal systemic side effects, and has been successfully used in post-menopausal women to produce amenorrhoea while taking hormone replacement therapy.4 Gynaecologists have striven for many years to find effective, safer surgical alternatives to hysterectomy in the management of women with menstrual disorders. Their efforts have led to the introduction of endometrial ablation techniques. A pragmatic, randomised controlled trial comparing microwave endometrial ablation with hysteroscopic surgery found equally high rates of patient satisfaction, acceptability, and improved quality of life, with amenorrhoea present in 40% of women treated in both groups at 1 year.5 While some women wish for amenorrhoea, promoting the oral contraceptive as a panacea cannot be justified at present. *P McGurgan, P O’Donovan, S Duffy, L Rogerson *M.E.R.I.T. Centre, Bradford Royal Infirmary, Bradford BD9 6RJ, UK; St James Hospital, Leeds 1
2
3 4
5
Thomas SL, Ellerston C. Nuisance or natural and healthy: should monthly menstruation be optional for women? Lancet 2000; 355: 922–24. Committee on Safety of Medicines Combined Oral Contraceptives and Thromboemboli. London: Committee on Safety of Medicines 1995. Guillebaud J, ed. Contraception Today, 3rd edn. London: Martin Dunitz Ltd, 1998. Suvanto-Luukkonen E, Kauppila A. The levonorgestrel intrauterine system in menopausal hormone replacement therapy: fiveyear experience. Fertil Steril 1999; 72: 161–63. Cooper KG, Bain C, Parkin DE. Comparison of microwave endometrial ablation and trans-cervical resection of the endometrium for treatmenr of heavy menstrual loss: a randomised trial. Lancet 1999; 354: 1859–63.
THE LANCET • Vol 355 • May 13, 2000
teenage pregnancy) also need to be addressed. Deborah A Cohen, *Thomas A Farley Louisiana State University Health Science Campus, Department of Public Health and Preventive Medicine, New Orleans, LA, USA; and *Louisiana Office of Public Health, 325 Loyola, New Orleans, LA 70112, USA 1
2
Hicks D. Is there a case for school-based screening for sexually transmitted diseases? Lancet 2000; 355: 864. Burstein GR, Gaydos CA, Drener-West M, Howell MR, Zenilman JR, Quinn TC. Incident chlamydia trachomatis infections among inner-city adolescent females. JAMA 1998; 280: 521–26.
this subject is thus desirable since it relates to fundamental issues in medicine, and the meaning and use of science and evidence in general. The newer post-normal science of chaos can bridge the gap between evidence and reality,3 and also reduce the culture gap between scientists and others, which Brewin notes, Snow discussed 40 years ago. V S Rambihar Scarborough Hospital, 3050 Lawrence Ave E, Toronto M1P 2V5, Canada (e-mail: [email protected]) 1
Science, evidence, and the use of the word scientific Sir—Science keeps changing and Thurstan Brewin’s jab at the use of the word “scientific” (Feb 12, p 586)1 invites an even deeper exploration of science and its relation to our understanding of evidence and reality. Hippocrates (450 BC) sought natural explanations for observed phenomena, changing the world-view from divine intervention and supernatural causes, and creating a new Greek science.2 Newton imposed structure and predictability on the world as a clockwork universe leading to Classical Science (1600–1900). Modern Science (since 1900s) provided us with a probabilistic universe and ultimate reductionism, all the way from quarks to quasars. A postmodern science has developed since the 1980s, of deconstructionism, responding to the collapse of normal science. Normal science (before 2000) refers to a puzzle solving approach, with uncertainty managed and values unspoken. A post-normal (not postmodern) science has since appeared, emerging from the new science of nonlinear dynamics, which recognises irregularity, subjectivity, and uncertainty as intrinsic and fundamental.3–5 This new science is variously also called chaos, complexity, or nonlinear dynamics. Science or evidence lies in the eye of the beholder, changing with time, place, and circumstance. Science may mean absolute truth and validity to some, with a relentless pursuit of certainty, whereas others may accept the inevitability of uncertainty, and the contextual and thus subjective nature of reality. The nature of evidence could now be considered contextual and changing. Brewin describes this changing concept of evidence when he decries ignoring explanations for phenomena “that on later reflection are equally possible”, and when he advocates weighing lack of evidence partly on “how much effort has been made to find it”. More general education, discussion, and debate on
1730
2
3
4 5
Brewin T. Use of the word “scientific”. Lancet 2000; 355: 586. Rambihar VS. CHAOS: from Cos to cosmos: a new art, science and philosophy of medicine . . . and everything else. Toronto: Vashna Publications, 1996. Rambihar VS. A new chaos based medicine beyond 2000: the response to evidence. Toronto: Vashna Publications, 1999. Kernick DP. After postmodernism. Lancet 2000; 355: 149. Funtowicz S, Ravetz J. Science for the postnormal age. Futures 1993; 25: 739–55.
Should menstruation be optional for women? Sir—We assume that Sarah Thomas and Charlotte Ellertson’s provocative essay (March 11, p 922)1 advocating amenorrhoea as a choice for women, best achieved through continuous use of oral contraceptive pill is intended to stimulate debate. What surprises us is the single-minded promotion of oral contraceptives as the only means by which to achieve this goal. As the pill scare, which followed a letter from the UK Committee on Safety of Medicines (CSM) on Oct 18, 1995,2 showed, the combined oral contraceptive pill can engender fear and distrust in physicians and patients. We know that any potential reported increase in complication rates amongst pill users will have important adverse repercussions for those women who most require effective contraception. Thomas and Ellerston neglect to mention that there are potential complications in prescribing continuous oral contraception, and that the use of the pill in this capacity represents an unlicensed indication with inherent medicolegal risks for the prescriber.3 Data from conventional use of oral contraceptive pill support the safety of the drug. The risk of death per annum from the pill is 1/3 the risk of dying as a result of an accident in the home, and 1/6 the risk of dying as a result of pregnancy.3 However, the oral contraceptive pill has deleterious effects on lipid metabolism and vascular disease. The pill-free interval whilst
producing pseudo menstruation, might have important systemic implications for long-term safety. HDL-cholesterol suppression is reversed by the end of the pill-free interval,3 this effect would be eliminated amongst continuous users of the oral contraceptive pill. What are the alternative available methods to provide amenorrhoea as a lifestyle choice for women? The only method to guarantee amenorrhoea is hysterectomy, but if women are prepared to accept hypomenorrhoea, or light spotting, as a compromise there are safe, effective medical and less radical surgical options. The levonorgestrel-releasing intrauterine system (Mirena LNG-IUS, Schering Health, West Sussex, UK) is a contraceptive with an unlicensed indication for the treatment of menorrhagia, producing a significant decrease in menstrual blood loss in 97% of women at 1 year follow-up. This contraceptive is well tolerated, lasts for 3–5 years with minimal systemic side effects, and has been successfully used in post-menopausal women to produce amenorrhoea while taking hormone replacement therapy.4 Gynaecologists have striven for many years to find effective, safer surgical alternatives to hysterectomy in the management of women with menstrual disorders. Their efforts have led to the introduction of endometrial ablation techniques. A pragmatic, randomised controlled trial comparing microwave endometrial ablation with hysteroscopic surgery found equally high rates of patient satisfaction, acceptability, and improved quality of life, with amenorrhoea present in 40% of women treated in both groups at 1 year.5 While some women wish for amenorrhoea, promoting the oral contraceptive as a panacea cannot be justified at present. *P McGurgan, P O’Donovan, S Duffy, L Rogerson *M.E.R.I.T. Centre, Bradford Royal Infirmary, Bradford BD9 6RJ, UK; St James Hospital, Leeds 1
2
3 4
5
Thomas SL, Ellerston C. Nuisance or natural and healthy: should monthly menstruation be optional for women? Lancet 2000; 355: 922–24. Committee on Safety of Medicines Combined Oral Contraceptives and Thromboemboli. London: Committee on Safety of Medicines 1995. Guillebaud J, ed. Contraception Today, 3rd edn. London: Martin Dunitz Ltd, 1998. Suvanto-Luukkonen E, Kauppila A. The levonorgestrel intrauterine system in menopausal hormone replacement therapy: fiveyear experience. Fertil Steril 1999; 72: 161–63. Cooper KG, Bain C, Parkin DE. Comparison of microwave endometrial ablation and trans-cervical resection of the endometrium for treatmenr of heavy menstrual loss: a randomised trial. Lancet 1999; 354: 1859–63.
THE LANCET • Vol 355 • May 13, 2000