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Biomedical subjects

A H MacLennan

Publications and source records attributed to A H MacLennan.

At least 19 recordsLinked to original sources
PubMed2005

Current status of hormone therapy and breast cancer.

This editorial comments on two similar reviews of the literature on breast cancer and post-menopausal hormone therapies (HTs), puts the results in clinical perspective and suggests where they direct future research and clinical management. Although epidemiological studies have suggested increased breast cancer risk for all menopausal HT regimens, unopposed oral estrogen regimens have not been associated with any increased risk in recent randomized placebo controlled trials (RCTs). Added progestogen after 5 years of combined HT in RCTs increases the risk of breast cancer by four cases per 10,000 per annum. As yet there is no evidence of different risk by progestogen type, dose or route. Theoretically local intrauterine progestogen may not give the same risk, but long-term trials are required. The commentary addresses the responsibility of the media in presenting levels of risk to the public, moving towards safer regimens, safer therapies, appropriate patient choice and, in particular, correct timing of HT where it is prescribed around menopause. This is in contrast to many of the trials when HT was administered after the potential climacteric window of therapeutic opportunity. The current main indication for HT remains for menopausal symptom control where it improves quality of life. HT may be required for many years. The informed woman should decide on HT based on her personal benefits and risks, which should include all aspects of her health.

Breast Neoplasms↗
PubMed2004

Hormone therapy use after the Women's Health Initiative.

OBJECTIVE: To continue surveillance of hormone therapy (HT) use in an Australian population and to assess the impact of the Women's Health Initiative (WHI) and associated reports on HT use 16 months after the results of the WHI were first reported. METHODS: Data were obtained from the 2003 South Australian Health Omnibus Survey, which involves a representative, population face-to-face interview survey. Data were compared to five surveys undertaken between 1991 and 2000, which had consistent methods and quality-control procedures. A total of 907 interviews were conducted with women over 40 years in their own homes by trained health interviewers. RESULTS: In association with the timing of media reporting of the WHI, current HT use rates dropped from 28% in women over 50 years in 2000 to an estimated 10.2% in 2002. By October 2003, current use rates had returned to 18.8% in this age group. The media had been the main influence in the women's decision-making. Half of those who restarted therapy changed to another type of HT. Only 2.8% changed to an alternative/complementary therapy. CONCLUSIONS: Nearly two-thirds (64%) of those currently using HT in 2002 stopped therapy, mostly in response to the media reporting of the WHI. Nearly half of those who stopped HT in 2002 have since restarted. Media reporting greatly influences the use of hormonal therapies.

Adult↗
PubMed2004

Use and perception of hormone therapy following media reports of the Women's Health Initiative: a survey of Australian WISDOM participants.

OBJECTIVES: To investigate the impact of the Women's Health Initiative (WHI) on the use and perception of hormone therapy (HT) in well-informed and altruistic women who had volunteered for a similar long-term study of HT (Women's International Study of long Duration Oestrogen after Menopause, WISDOM). METHODS: A total of 840 South Australian WISDOM participants were sent questionnaires asking about their source of information about the WHI, interpretation of the 2002 WHI findings, perception of HT as a risk factor for breast cancer, attitudes towards doctors and the media and intent to use HT in the future. RESULTS: Altogether, 618 participants (74%) responded. Written and verbal information provided by WISDOM were rated as the most helpful sources of information about the WHI. Participants were aware of the increase in breast cancer and decrease in fractures seen with combined estrogen/progestogen hormone therapy (EPT) but were less convinced about the other major findings, including cardiovascular disease and dementia. HT was rated as an important risk factor for breast cancer. Participants valued medical research and were more likely to question therapies without evidence. After WHI and WISDOM, most were willing to participate in a subsequent trial and most past HT users resumed therapy. CONCLUSIONS: There are sufficient recruits for future long-term HT studies if they are given sufficient quality information and individual counselling. Our study also suggests that women who are appropriately informed may choose to take long-term HT despite a more conservative approach advised by some agencies.

Adult↗
PubMed2002

Hormone replacement therapy use over a decade in an Australian population.

OBJECTIVES: To describe the prevalence of hormone replacement therapy (HRT) during the 1990s in an Australian population and the length of time this therapy has been used. Design Data were obtained from five biennial representative population face-to-face interview surveys of the South Australian population from 1991 to 2000, and an additional telephone survey in 2001. The main surveys used consistent methods and quality control procedures. PARTICIPANTS: Over 3000 South Australian adults were interviewed in their own homes by trained health interviewers in each of the biennial surveys. RESULTS: In 2000, 28% of women aged over 50 were currently using HRT, and ever-use of HRT was 43%. Highest use of HRT was in the 55-59-year age group, where current use was 47% and ever-use was 70%. Among women 55 years and older there was a statistically significant increase in the prevalence of HRT use between 1991 and 2000. Mean length of use in women aged over 55 years increased from 5.4 years in 1991 to 9.6 years in 2000. CONCLUSIONS: Consistent surveillance of the population has shown that HRT use has not increased before age 55, but has greatly increased thereafter. Long-term effects may now be occurring, and further results of current long-term randomized trials are awaited to confirm the overall risk/benefit ratio suggested by observational studies and early results from long-term trials.

Adult↗
PubMed2001

How long does it take to deliver a baby by emergency Caesarean section?

This audit documented the current range of decision-to-delivery reaction times for 464 emergency Caesarean sections performed in maternity hospitals with differing levels of facilities, and examined the reasons for any perceived delay. The median (with 10th-90th percentile) times from when the decision was made to perform an emergency Caesarean section to the delivery of the child were: 69 (37-114), 54 (28-94) and 42 (17-86) minutes in Level 1, 2 and 3 maternity hospitals respectively when the indication for delivery was urgent. Less urgent emergency Caesarean sections took 70 (42-125), 66 (38-141) and 67 (35-164) minutes respectively. The main perceived reasons for delay in the delivery were staff unavailability in Level 1 hospitals, theatre access in Level 2 hospitals and anaesthetic complications in Level 3 hospitals. Therefore the decision-to-delivery reaction times in the majority of urgent emergency Caesarean sections are, in practice, much longer than the times commonly advocated and are influenced by the facilities and staff available.

Cesarean Section↗
PubMed2000

The prevalence of pelvic floor disorders and their relationship to gender, age, parity and mode of delivery.

OBJECTIVE: To define the prevalence of pelvic floor disorders in a non-institutionalised community and to determine the relationship to gender, age, parity and mode of delivery. DESIGN: A representative population survey using the 1998 South Australian Health Omnibus Survey. SAMPLE: Random selection of 4400 households; 3010 interviews were conducted in the respondents' homes by trained female interviewers. This cross sectional survey included men and women aged 15-97 years. RESULTS: The prevalence of all types of self-reported urinary incontinence in men was 4.4% and in women was 35.3% (P<0.001). Urinary incontinence was more commonly reported in nulliparous women than men and increased after pregnancy according to parity and age. The highest prevalence (51.9%) was reported in women aged 70-74 years. The prevalence of flatus and faecal incontinence was 6.8% and 2.3% in men and 10.9% and 3.5% in women, respectively. Pregnancy (> 20 weeks), regardless of the mode of delivery, greatly increased the prevalence of major pelvic floor dysfunction, defined as any type of incontinence, symptoms of prolapse or previous pelvic floor surgery. Multivariate logistic regression showed that, compared with nulliparity, pelvic floor dysfunction was significantly associated with caesarean section (OR 2.5, 95% CI 1.5-4.3), spontaneous vaginal delivery (OR 3.4, 95% CI 2.4-4.9) and at least one instrumental delivery (OR 4.3, 95% CI 2.8-6.6). The difference between caesarean and instrumental delivery was significant (P<0.03) but was not for caesarean and spontaneous delivery. Other associations with pelvic floor morbidity were age, body mass index, coughing, osteoporosis, arthritis and reduced quality of life scores. Symptoms of haemorrhoids also increased with age and parity and were reported in 19.9% of men and 30.2% of women. CONCLUSION: Pelvic floor disorders are very common and are strongly associated with female gender, ageing, pregnancy, parity and instrumental delivery. Caesarean delivery is not associated with a significant reduction in long term pelvic floor morbidity compared with spontaneous vaginal delivery.

Adolescent↗
PubMed2000

Haematopoietic indicators of fetal metabolic acidosis.

We aimed to study the haematopoietic response in normal and acidotic deliveries following vaginal and abdominal delivery and to compare this to the surrogate markers of perinatal acidosis. Blood gas analyses, complete blood pictures and erythropoietin assays were performed on umbilical or early neonatal blood samples. Placental sections were examined for the presence of nucleated red blood cells. Perinatal clinical risk factors and major neonatal outcomes were collected. The control population was 78 deliveries where the cord arterial pH was > 7.10. Controls born after labour were compared to those born prior to the onset of labour and to 14 acidotic infants born after labour. Nucleated red blood cells did not increase with labour in the control groups but were significantly higher (p < 0.05) in the acidotic group. Erythropoietin did not significantly change with either labour or acidosis. The predictive values from nucleated red blood cell counts were higher than those from low Apgar scores, atypical cardiotocograph traces, meconium-stained amniotic fluid, erythropoietin and the presence of nucleated red blood cells in placental sections. Nucleated red blood cell counts may be a useful surrogate marker of acidosis where blood gas analysis is unavailable. Further studies are required to examine the timing of the increase of erythropoiesis to help define the onset of the stimulus.

Acidosis↗
PubMed2000

WISDOM. Will Australian women participate?

AIM: This study investigated the likelihood of 50-69 year old women participating in the Women's International Study of long Duration Oestrogen after Menopause (WISDOM)--a 10 year randomised placebo controlled trial of hormone replacement therapy involving 10 years treatment plus a further 10 years follow up of major health outcomes. METHODS: The Health Monitor 2 (a representative population telephone survey) was used. Participants were 268 women aged 50-69 years from a total survey population of 2003 adults. Sociodemographic characteristics were collected. RESULTS: Of the women surveyed 20.9% indicated they were likely to participate and this was independent of sociodemographic characteristics and self reported health status. Women aged 50-54 were more likely to participate than older women. DISCUSSION: After allowing for exclusion criteria, it is estimated that approximately 10% of 50-69 year old women approached for recruitment in WISDOM may actually participate. There are likely to be sufficient altruistic women in this population to run WISDOM in Australia.

Aged↗
PubMed1999

Hormone therapy use in Australian-born women: a longitudinal study.

OBJECTIVES: To describe the pattern of use of hormone therapy (HT) among Australian women, and its side-effects and benefits, and to compare baseline characteristics of HT users with never users. DESIGN: Longitudinal community-based study with annual interviews. SETTING: Melbourne, May 1991-October 1997. PARTICIPANTS: 357 Australian-born women aged 45-55 years who were pre- or perimenopausal and not using HT at baseline. MAIN OUTCOME MEASURES: Rates of HT use; baseline characteristics of users and non-users; side effects and benefits of HT use. RESULTS: 151 women (42%) used HT over the six years and 93 (26%) were current users at six-year follow-up. HT users did not differ significantly from non-users in lifestyle, sociodemographic and cardiovascular risk factors or in most health status factors at baseline. However, HT users were significantly more likely to have had a breast examination by a health professional (odds ratio [OR], 2.60; 95% CI, 1.62-4.17), to have had a tubal ligation (OR, 1.73; 95% CI, 1.09-2.74), to report a history of premenstrual complaints (OR, 1.72; 95% CI, 1.08-2.74), to agree that women "regret when their period stops for the last time" (OR, 1.69; 95% CI, 1.04-2.74), and to report that they took non-prescription medications (OR, 1.62; 95% CI, 1.02-2.59). Most (84%) HT users described benefits (most commonly relief of hot flushes and improved wellbeing), while 53% complained of side effects (most commonly weight gain and breast tenderness). CONCLUSIONS: HT users did not differ significantly from non-users at baseline in most characteristics. Long-term follow-up of this cohort is now required to assess any difference in cardiovascular events or other health outcomes between HT users and non-users.

Australia↗
PubMed1999

Hormone replacement therapies in women at risk of cardiovascular disease and osteoporosis in South Australia in 1997.

OBJECTIVE: To describe changes in use of hormone replacement therapy (HRT) in an Australian population and to determine HRT use in women at risk of cardiovascular disease and osteoporotic fracture. DESIGN: Data were derived from the 1997 South Australian Health Omnibus Survey (a representative population survey) and compared with data from 1991, 1993 and 1995 Omnibus Surveys. SETTING: South Australia, 1997. PARTICIPANTS: 1049 women aged 40 years and over from a random selection of 4400 households. RESULTS: Among women aged 55-64 years (and thus likely to be postmenopausal), 60% had used HRT (ever use). Nearly two-thirds of these women used it currently. In this age group, mean length of HRT use had increased to 70 months (median, 60 months). Rates of HRT use had not changed significantly between 1991 and 1997 in women under 55 years, but had increased significantly in women aged 55 years or over (P < or = 0.01). Among women currently using HRT, 5.4% had used testosterone therapy, while 4% used unregistered products purported to contain hormones. Rates of ever use of HRT in women with zero, one, two, or three or more cardiovascular risk factors were 33%, 37%, and 45%, respectively. Among women with a diagnosis of osteoporosis, 52% had used HRT, with a mean length of use of 86 months (median, 60 months). CONCLUSION: HRT use is increasing in older-age groups. Longer-term therapy with potential for primary prevention is now occurring, but half of those with osteoporosis and more than half of those with risk factors for cardiovascular disease have not used HRT.

Adult↗
PubMed1998

Where is the evidence for effectiveness of treatments for the menopause? Introducing the Cochrane Collaboration.

The past two decades have seen an explosion of research surrounding the menopause. This ever-increasing volume of research has made it an impossible task for health professionals involved in the management of the menopause to be able to assimilate the information easily. There is an urgent need for the findings from research to be synthesized into simple, easy-to-read reviews that are of high quality and are based on the best evidence available. The Menstrual Disorders and Subfertility Group of the Cochrane Collaboration is attempting to address these issues by collecting a register of all the randomized controlled trials in the treatments of the menopause and preparing systematic reviews on a number of topics that will be of interest to health-care workers and consumers. Readers are invited to participate in this process by identifying published and unpublished data and by helping in the process of preparing protocols and systematic reviews for inclusion in the Cochrane Library.

Evidence-Based Medicine↗
PubMed1998

Hormone replacement therapy: prevalence, compliance and the 'healthy women' notion.

BACKGROUND: The objective of this study was to assess the current trends of hormone replacement therapy (HRT) use, including rates of use, length of use, continuation rates and characteristics of users and non-users and to examine the hypothesis that 'healthy women' are more likely to be users of HRT. METHODS: Analysis was carried out of three representative South Australian population studies in 1991, 1993 and 1995 comprising 3019, 3004 and 3016 personal interviews, respectively. RESULTS: Current use (and ever-use) of HRT in all women aged 50 years and over rose from 13.2% (26.7%) in 1991, to 21.2% (31.9%) in 1993 and 26.0% (40.5%) in 1995. Highest use is now in the 55-59-year age group where, in 1995, current use was 50.9% and ever use was 69.0%. Median compliance rates with HRT rose from 24 months in 1991 to 60 months in 1995 for current users aged 50 years of age or above. The pattern of increasing use of HRT is not consistent across age groups. Analyses of the 1995 data show that, in contrast with increasing rates of current use in women over 55 years, there was no overall change in rates for women below this age. There were no statistically significant differences in health indicators, e.g. blood pressure, smoking, cholesterol levels or body mass index between users and non-users of HRT. However, users reported significantly higher rates of previous osteoporosis and hysterectomy. CONCLUSIONS: Prevalence rates of HRT use are increasing together with compliance rates and this may reflect increased confidence with HRT therapy. Users of HRT have an increased rate of mammography compared to non-users and this may contribute to earlier detection and, therefore, increased estimates of breast cancer in HRT users. There was no support from the 1995 data for a 'healthy women' hypothesis among HRT users.

Age Factors↗
PubMed1998

Health status of hormone replacement therapy users and non-users as determined by the SF-36 quality-of-life dimension.

BACKGROUND: The objective of this study was to compare the health status of women who use and do not use hormone replacement therapy (HRT). METHOD: The 1994 South Australian Health Omnibus Survey (a population health interview survey) was used to administer the short form-36 health survey questionnaire (SF-36) to users and non-users of HRT. A representative sample of 813 women aged 40 years and older were interviewed. The response rate of the survey was 72.4%. Eight health dimensions of the SF-36 were measured: physical functioning, social functioning, role limitations owing to emotional problems, role limitations owing to physical problems, mental health, vitality, pain and general health. RESULTS: The mean score for all eight health dimensions was in the bottom 50% of the population for HRT users while non-users were in the upper 50%. Users of HRT had significantly poorer scores for physical limitations, body pain, general health, vitality, social functioning and mental health. CONCLUSION: Women who use HRT are less healthy than non-users when measured by a generic health status measure.

Adult↗