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N Dickson

Publications and source records attributed to N Dickson.

At least 19 recordsLinked to original sources
PubMed2006

Risk of herpes simplex virus type 2 acquisition increases over early adulthood: evidence from a cohort study.

UNLABELLED: DESIGN/ SETTING: A cohort study of 1037 people born in Dunedin, New Zealand, in 1972 or 1973. PARTICIPANTS: At assessment at age 32 years, 884 participants (432 women and 452 men; 87.1% of the surviving cohort) provided both sera and information on sexual behaviour. MAIN OUTCOME MEASURES: The proportion of participants with antibodies to HSV-2 infection at ages 26 and 32 years was measured, and the incidence rates from first coitus to age 26 years and from age 26 to 32 years calculated, adjusting for the number of sexual partners and same-sex contact in these age periods. RESULTS: At age 32 years, 14.6% of men and 22.5% of women had antibodies to HSV-2. The incidence rates for men and women from first coitus to age 26 years were, respectively, 6.5 and 14.3 per 1000 person-years. The incidence rates for men and women from age 26-32 years, respectively, were 14.3 and 15.8 per 1000 person-years. When adjusted for sexual behaviour, the incidence rate ratio, comparing the older with the younger age periods, was 2.9 (95% confidence interval (CI) 1.7 to 4.9) for men and 2.0 (1.2 to 3.4) for women. The adjusted incidence rate ratio when comparing women to men from first coitus to age 26 years was 2.5 (1.6 to 4.0), and from age 26-32 years was 1.3 (0.78 to 2.2). A test for interaction indicated that men and women had different patterns of incidence over time (p = 0.039). CONCLUSION: In the general population, the risk of acquiring HSV-2 infection seems to increase with age at least to the early 30s, and differences in risk of acquisition for women compared with men become less with age. Health promotion and treatment to control HSV-2 infection should be aimed at all ages, not just at the young.

Adult↗
PubMed2001

Performance comparison of suspended bed and batch contactor chromatography.

In some applications, the purification and recovery of biomolecules is performed via a cascade of batch adsorption and desorption stages using agitated contactors and related filtration devices. Suspended bed chromatography is a recent process-scale innovation that is applicable to these separations. This hybrid technique exploits the benefits of combining batch adsorption in an agitated contactor with elution in an enclosed column system. To some extent, the process is similar to batch contactor chromatography but can be fully contained and significantly quicker. The process has two steps; first the fluid containing the sample is mixed with the adsorbent in a stirred tank. Second, the slurry suspension is transferred directly into a specialized column, such as an IsoPak column. The media with the adsorbed product is formed as a packed bed, whilst the suspension liquid is passed out of the column. The product is then eluted from the packed bed utilizing standard column-chromatography techniques. The performance of the suspended bed and the agitated contactor operations are demonstrated both by full-scale experimental results and process simulations. The purification of ovalbumin from a hen-egg white feedstock by anion-exchange chromatography was used as a case study in order to prove the concept. With the availability of both pump-packed systems and shear-resistant media, suspended bed chromatography is a better alternative for a range of applications than the traditional batch separations using agitated contactors.

Adsorption↗
PubMed2001

Unwanted pregnancy and contraceptive knowledge: identifying vulnerable groups from a randomized controlled trial of educational interventions.

OBJECTIVES: The aim of this study was to identify predictors of contraceptive pill knowledge and their relationship to educational interventions. METHODS: A total of 636 women attending for a follow-up appointment for repeat prescription of the combined oral contraceptive pill with a GP or practice nurse were randomized to receive leaflets (simple summary leaflet or FPA leaflet), advice or neither. Sociodemographic details and contraceptive knowledge were determined using a validated contraceptive knowledge questionnaire sent after 3 months by post. The main outcomes were sociodemographic, contraceptive, attitudinal and educational predictors of knowledge. RESULTS: A total of 522 (82%) had complete questionnaires. After controlling for educational intervention and other confounding variables, independent predictors of knowledge were further education (adjusted odds ratio 2.98, 95% confidence interval 1.78-4.99); number of years on the pill (0-5, 6-10, >10 years) 1.0, 0.56 (0.33-0.95) and 0.34 (0.19-0.59), respectively; past emergency contraception (1.87, 1.18-2.97); and importance attached to not falling pregnant (1.83, 1.02-3.29). These predictors are less powerful than the impact of most educational interventions (range of odds ratios for interventions: 1.85-6.81), and there was no evidence of a separate effect of educational intervention in any subgroup, except that leaflets have a larger effect in women who have needed emergency contraception in the past (no past use or simple summary and FPA leaflets, 1.74 and 0.90, respectively; with past use, 3.47 and 3.83; interaction term chi-square 6.92, P = 0.03). CONCLUSION: Educational interventions are as important as sociodemographic features in determining knowledge. With limited time for full educational interventions in practice, priorities for intervention should be women who have used emergency contraception in the past-who will benefit most-and those on the pill for >5 years or with no further education who are at highest risk due to poor knowledge.

Adult↗
PubMed2001

Predicting early fatherhood and whether young fathers live with their children: prospective findings and policy reconsiderations.

This prospective study of a birth cohort addressed three questions. Which individual and family-of-origin characteristics predict the age at which young men make the transition to fatherhood? Do these same characteristics predict how long young men live with their child? Are individual differences in the amount of time fathers spend living with their child associated with the father's psychosocial characteristics in young adulthood? In this unique study, it was found that by age 26, 19% of the 499 study men had become fathers. Individual and family-of-origin characteristics were assessed from birth until age 15 and contemporaneous characteristics were assessed at age 26. Young men who experienced a stressful rearing environment and a history of conduct problems were more likely to become fathers at an early age and to spend less time living with their child. Of those who experienced none of the risk factors, fewer than 10% had become fathers by age 26 compared to more than 60% of those who experienced five risk factors. Fathers who lived apart from their child reported the most social and psychological difficulties in young adulthood. These findings point to individual and family-of-origin characteristics that might be targeted in order to delay fatherhood and increase levels of paternal involvement. However, given their troubled life histories and poor social-psychological adjustment in young adulthood, some absent fathers might have difficulties providing positive parenting and partnering unless policy initiatives to promote intact families also support young fathers.

Adolescent↗
PubMed2000

Enhanced surveillance of HIV infections in New Zealand, 1996-1998.

AIM: To improve understanding of the HIV epidemic in New Zealand through use of an enhanced voluntary reporting system for new diagnoses of HIV. METHODS: Routine reporting of new HIV diagnoses by the two laboratories that perform confirmatory HIV antibody testing, to the Department of Health and later to the AIDS Epidemiology Group, has been in place since 1985. From January 1996, this was supplemented by a questionnaire about demographic characteristics and circumstances of HIV exposure sent to clinicians requesting the HIV test. RESULTS: From January 1996 to December 1998, 260 new diagnoses of HIV were reported (205 males, 55 females) and extra information was obtained from clinicians for 253 (97.3%) people. HIV diagnosis rate was highest for 'other' ethnicity and similar for European, Maori and Pacific Island ethnic groups. Sexual intercourse between men was the commonest mode of infection (43.5%), followed by heterosexual intercourse (40.0%) and injecting drug use (2.7%). Places of infection were New Zealand (38.5%), Australia (7.7%), 'other' overseas (45.4%) and unknown (8.5%). Heterosexual infections were acquired through contact with a person in or from a high prevalence area (mainly in Africa or Asia) for 86.7% of males and 68.2% of females. Second generation heterosexual transmission was rare. CONCLUSIONS: Introduction of an enhanced surveillance system has been successful. Results confirm continuing spread of HIV in New Zealand amongst men who have sex with men, and suggest low levels of heterosexual and injecting drug use transmission in New Zealand. Of major importance in the occurrence of heterosexual infection is the role of imported HIV.

Adolescent↗
PubMed2000

Suspended bed chromatography, a new approach in downstream processing.

A new technique in downstream processing, suspended bed chromatography has been developed. This hybrid technique exploiting the benefits of batch adsorption and the process advantages of an enclosed column system can be carried out using established contactors and adsorbents. A 44 cm I.D. IsoPak column and the anion-exchange cellulose Express-Ion Exchanger Q were used in the purification of ovalbumin from hen-egg white. After suspension of 16.25 kg Express-Ion Q in 500 l of feedstock containing 5 g protein/l, adsorption was effected by recirculation of the suspension using the IsoPak slurry preparation station. Protein-loaded adsorbent was collected in the IsoPak column unit, where it was washed and protein desorbed using gradient elution at a flow-rate of 300 cm/h. The entire process was complete in under 3 h. With the introduction of pump-packed column systems and the availability of mechanically strong adsorbents suitable for column separations, suspended bed chromatography offers a new approach to downstream processing and provides a less challenging alternative to batch separations.

Adsorption↗
PubMed2000

Psychiatric disorders and risky sexual behaviour in young adulthood: cross sectional study in birth cohort.

OBJECTIVE: To determine if risky sexual intercourse, sexually transmitted diseases, and sexual intercourse at an early age are associated with psychiatric disorder. DESIGN: Cross sectional study of a birth cohort at age 21 years with assessments presented by computer (for sexual behaviour) and by trained interviewers (for psychiatric disorder). SETTING: New Zealand in 1993-4. PARTICIPANTS: 992 study members (487 women) from the Dunedin multidisciplinary health and development study. Complete data were available on both measures for 930 study members. MAIN OUTCOME MEASURES: Psychiatric disorders (anxiety, depression, eating disorder, substance dependence, antisocial disorder, mania, schizophrenia spectrum) and measures of sexual behaviour. RESULTS: Young people diagnosed with substance dependence, schizophrenia spectrum, and antisocial disorders were more likely to engage in risky sexual intercourse, contract sexually transmitted diseases, and have sexual intercourse at an early age (before 16 years). Unexpectedly, so were young people with depressive disorders. Young people with mania were more likely to report risky sexual intercourse and have sexually transmitted diseases. The likelihood of risky behaviour was increased by psychiatric comorbidity. CONCLUSIONS: There is a clear association between risky sexual behaviour and common psychiatric disorders. Although the temporal relation is uncertain, the results indicate the need to coordinate sexual medicine with mental health services in the treatment of young people.

Adult↗
PubMed2000

Pregnancies among New Zealand teenagers: trends, current status and international comparisons.

AIMS: To examine trends in birth and total pregnancy rates among teenage women in New Zealand, ethnic differences and international comparisons. METHODS: Routinely collected data on births and abortions by age in New Zealand have been used to derive teenage birth rates and estimated total teenage pregnancy rates. RESULTS: The teenage birth rate rose from the end of the Second World War until 1972, then dropped until 1986, since when it has risen slightly. An increase in the proportion of teenage pregnancies aborted since 1986 has prevented a more marked increase in the birth rate. In 1997, the teenage birth rate for Maori was nearly five times, and the Pacific rate over three times, that of European/Pakeha teenagers. Although the abortion rate was slightly higher among Maori than European/Pakeha teenagers, Maori who became pregnant were much less likely to have an abortion. Of the developed OECD countries, only the USA has a higher teenage birth rate than New Zealand. However, the teenage birth rate among European/Pakeha in New Zealand, while higher than in many Western European countries, is similar to the total rate in Australia, and less than that in the UK and Canada. CONCLUSIONS: This analysis shows that using routinely collected data, it is possible to monitor national teenage pregnancy rates. Improvements in monitoring could be made by collecting ethnicity data on abortions and births in a consistent manner, together with the area of residence of women having abortions. The findings indicate the importance of understanding the impact on Maori women who become pregnant as teenagers and on their children.

Abortion, Induced↗
PubMed2000

Sexual abstinence at age 21 in New Zealand: the importance of religion.

Most research on adolescent sexual behaviour has focused on early initiation and consequent risks. We have instead examined the circumstances of young people who have not had sexual intercourse before age 21, in order to throw light on the ways in which young people might resist societal pressures for early sexual intercourse. The sample was a cohort born in Dunedin, New Zealand in 1972/73, formed at age 3, and followed with regular assessments of personal, family and educational functioning to age 21. At age 18 and 21 information on sexual behaviour was collected, using a computer presented questionnaire. The response rate at age 21 was 935/1020 (91.7%) of the survivors of the original cohort. Overall 11.3% of the men and 8.1% of the women reported never having sexual intercourse. Sex with a man was reported by 20 men (4.5%), of whom only two reported having sex only with men. Being first born and being persistently involved in religious activities, measured at both 11 years and 21 years, were significant predictors of abstinence for both sexes. Examination of perceptions of an ideal lifestyle, sexual behaviour and religious involvement showed that religion was an important factor in decisions to delay sexual intercourse past age 20, especially for men. It would be helpful to examine further the features of moral decision making which are characteristic of religious experiences.

Adult↗
PubMed2000

The determinants of sexual intercourse before age 16.

PURPOSE: To identify risk and protective factors for initiation of sexual intercourse before age 16 years at the level of the individual, family, and school. METHODS: A longitudinal study based on a cohort of 1020 people born in Dunedin, New Zealand in 1972/73 and followed up to age 21 years. Demographic characteristics of the sample were similar to the New Zealand population of that age, except that a smaller proportion (3%) were Maori or Pacific Island Polynesian. Information on individual, family and school factors was collected by interview with parents at ages 3, 5, 7 and 9 years and then by postal questionnaire two-yearly up to 15 years. Subjects were assessed two-yearly from age 3 years and interviewed about their behaviours and ambitions at ages 11, 13, and 15 years. Questions about age at first intercourse were asked by computer at age 21 years. Multivariate logistic regression was used to model associations with age of first intercourse less than 16 years. RESULTS: Data on age at first intercourse were available for 926/1020 (91%) of surviving members of the cohort assembled at age 3 years. Overall 27.5% of males and 31.7% of females reported sexual intercourse before age 16 years. In multivariate analyses the independent predictors for early sexual initiation for males were: not having outside home interests at age 13 years, no religious activity at age 11 years, not being attached to school at age 15 years, a low reading score, and a diagnosis of conduct disorder in early adolescence. For females, independent predictors were: socioeconomic status in the middle range, mother having her first child before age 20 years, IQ in the middle range, not being attached to school, being in trouble at school, planning to leave school early, cigarette smoking and higher self-esteem score. CONCLUSIONS: Individual and school factors appear to be more important than family composition or socioeconomic status in the decision to have sexual intercourse before age 16 years. The lowering of age at first intercourse may be partly a cohort effect related to high rates of teenage childbearing in the mothers' generation, and to changes in social acceptability of early sexual behaviour.

Adolescent↗
PubMed2000

Tension between policy and practice.

This is the first in a series of articles in which the political influences on the health service are examined. Niall Dickson, currently Social Affairs Editor with the BBC, gave this paper at Congress 1999--which had the overall theme of Rewind, Pause, Fastforward. Niall Dickson is a former editor of Nursing Times (1983-1988) and he has a continuing interest in matters affecting health and social policy.

Health Policy↗
PubMed1998

Effect of educational leaflets and questions on knowledge of contraception in women taking the combined contraceptive pill: randomised controlled trial.

OBJECTIVE: To assess whether provision of educational leaflets or questions on contraception improves knowledge of contraception in women taking the combined contraceptive pill. DESIGN: Randomisation of women into three groups according to type of educational leaflet on contraceptive information. These groups were subdivided into two on the basis of questions on contraception asked by the doctor or practice nurse. The women were followed up by postal questionnaire 3 months later. SETTING: 15 general practices in South and West region. SUBJECTS: 636 women attending check up appointment for repeat prescription of the combined contraceptive pill. MAIN OUTCOME MEASURES: Knowledge of: factors causing pill failure, subsequent action, emergency contraception, and all the rules (pill rules) that apply to the contraceptive pill. RESULTS: 523 women returned completed questionnaires (response rate 82%). Knowledge of contraception with no intervention was low with only 10 (12%) women knowing all the pill rules. Educational intervention had a highly significant effect on knowledge of: factors causing pill failure (likelihood ratio chi2=22); subsequent action (21); emergency contraception (24); and all the pill rules (22) (P<0.01 in all cases). Improvement in knowledge of all the pill rules occurred with provision of the summary leaflet (28% knew all the rules, adjusted odds ratio 4.04, 95% confidence interval 1.68 to 9.75), the Family Planning Association's leaflet (27%, 3.43, 1.45 to 8.09), and asking questions (26%, 3.03, 1.30 to 7.00). Asking questions in addition to provision of leaflets improved knowledge of contraception further for the summary leaflet (39%, 6.81, 2.85 to 16.27) but not for the Family Planning Association leaflet (21%, 2.58, 1.07 to 6.18). CONCLUSION: Women attending check ups for repeat prescriptions of the contraceptive pill should be provided with educational leaflets on contraception or asked relevant questions to help improve their knowledge of contraception. Asking questions in addition to providing a summary leaflet is time consuming, but results in the most knowledge gained.

Adolescent↗
PubMed1998

First sexual intercourse: age, coercion, and later regrets reported by a birth cohort.

OBJECTIVES: To investigate how age at first sexual intercourse is related to the reported circumstances and to determine how these corresponded to views in early adulthood about its timing. DESIGN: Cross sectional study within a birth cohort using a questionnaire presented by computer. SETTING: Dunedin, New Zealand in 1993-4. SUBJECTS: 477 men and 458 women enrolled in the Dunedin Multidisciplinary Health and Development Study, comprising 92% of survivors of the cohort. RESULTS: The median age at first intercourse was 17 years for men and 16 years for women. Only one man (0.2%) but 30 (7%) women reported being forced to have intercourse on the first occasion. For women, there were increasing rates of coercion with younger age at first intercourse. More men than women reported that they and their partner were equally willing (77% (316/413) v 53% (222/419)). Mutual willingness of both partners was greater for those who reported that it was also the first time for their partner. Timing of first intercourse was considered about right by 49% (200/411) of men and 38% (148/388) of women. Many women (54% (211/388) reported that they should have waited longer, and this rose to 70% (90/129) for women reporting intercourse before age 16. CONCLUSIONS: Most women regretted having sexual intercourse before age 16. First intercourse at younger ages is associated with risks that are shared unequally between men and women. This information is important to young people themselves.

Adult↗
PubMed1998

Adult physical health outcomes of adolescent girls with conduct disorder, depression, and anxiety.

OBJECTIVE: To examine the young adult physical health outcomes of adolescent girls with behavior problems. METHOD: Girls with conduct disorder, girls with depression, girls with anxiety, and healthy girls (N = 459) who had been evaluated at age 15 years were followed up at age 21, when general physical health, substance dependence, and reproductive health were assessed. RESULTS: After control for potentially confounding variables including prior health, adolescent conduct disorder predicted more medical problems, poorer self-reported overall health, lower body mass index, alcohol and/or marijuana dependence, tobacco dependence, daily smoking, more lifetime sexual partners, sexually transmitted disease, and early pregnancy. Adolescent depression predicted only adult tobacco dependence and more medical problems; adolescent anxiety predicted more medical problems. CONCLUSIONS: The robust link between female adolescent conduct disorder and poor physical health in adulthood suggests that intervention with girls who have conduct disorder may be a strategy for preventing subsequent health problems.

Adolescent↗
PubMed1998

Where young people with multiple sexual partners seek medical care: implications for screening for chlamydial infection.

OBJECTIVE: To investigate among young people the relation between the number of sexual partners and use of medical services in order to guide planning of sexually transmitted disease screening. DESIGN: Cross sectional study within a birth cohort using a questionnaire presented by computer. SETTING: Dunedin, New Zealand in 1993-4. SUBJECTS: 477 men and 458 women aged 21 enrolled in the Dunedin Multidisciplinary Health and Development Study, comprising 91.7% of survivors of the cohort. RESULTS: Men with multiple sexual partners in the previous year were less likely to have a general practitioner than men with one or no partners (76.2% v 88.5%, p < 0.01). Among the women the respective proportions (83.1% and 88.4%) were not significantly different. Significantly more women than men (75.8% v 50.7%, p = 0.03) with five or more partners in the previous year had visited their own general practitioner over that period. Among the sexually experienced, more women than men attended any setting appropriate for sexually transmitted disease screening (93.6% v 71.6%, p < 0.001). CONCLUSIONS: In New Zealand a screening programme for sexually transmitted diseases among young adults reliant on invitation by their own general practitioner would be biased towards those at less risk. Opportunistic screening in general practice would potentially include only about half the most sexually active men and three quarters of such women over a 12 month period. The extension of opportunistic screening to other settings considered appropriate for discussion of sexual health issues could potentially engage the vast majority of women, but not men, at most risk. Any screening programme should incorporate an effective method of finding and treating the sexual partners of infected women.

Adolescent↗