Biomedical subjects

R P Ford

Publications and source records attributed to R P Ford.

At least 19 recordsLinked to original sources

PubMed2001

SmokeChange for changing smoking in pregnancy.

AIM: To measure the extent to which SmokeChange, a personalised intervene, enabled pregnant women to rede their exposure to tobacco smoke. METHODS: A cross-section of general medical practices was randomly selected. General Practitioners (GPs) were to register all pregnant women with the SmokeChange programme. Smoking women were contacted by a SmokeChange Educator, who visited them at home. The Educator worked with women and their families for up to twelve months in order to support cognitive, environmental and behavioural changes to smoking. RESULTS: GPs registered 1,390 pregnant women. Current smoking, was reported by 437 (31.4%) and 209 (47.8% of smokers) chose to enrol with the SmokeChange intervention programme. of these, 149 women (34.1% of smokers) continued with the programme for at least four visits. From this 'long' participation group, 28 (18.8%) had stopped smoking entirely by their last visit in pregnancy. Another 26 (17.4%) reported at least one cessation attempt, together with a reduction of smoking consumption by 63% at the end of pregnancy. The 95 (63.8%) continued smokers had reduced their smoking consumption by 40%. Substantial smokefree environment (homes and cars) changes were also made. CONCLUSIONS: The SmokeChange approach of personalised intervention, matched to individual readiness for change, was both acceptable to pregnant women and enabled participants to substantially reduce tobacco toxin exposure to themselves and their developing infants.

Family Practice↗

PubMed2001

The burden of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema in children and adolescents in six New Zealand centres: ISAAC Phase One.

AIM: To describe the burden of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema in children in six New Zealand centres. METHODS: The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One was undertaken in Auckland, Bay of Plenty, Hawke's Bay, Wellington, Nelson and Christchurch during 1992-1993. In each centre, approximately 3,000 six to seven year old children and 3,000 thirteen to fourteen year old adolescents were studied, a total of 37,592 participants. Both age groups answered written questionnaires and the adolescents a video questionnaire about asthma symptoms. RESULTS: The prevalences of symptoms were high, for asthma 25% and 30%, allergic rhinoconjunctivitis 10% and 19%, and atopic eczema 15% and 13% in each age group respectively. More than 40% of participants had symptoms in the last year of at least one condition, most commonly asthma. There were no significant differences among regions, except for six to seven year olds in Nelson who had significantly lower prevalences of some symptoms of asthma and allergic rhinoconjunctivitis. CONCLUSIONS: Asthma and allergies are common in New Zealand, with resultant morbidity and cost. However, there is little regional variation with the exception of lower rates in Nelson children. Explanations for these findings will be the subject of further studies.

Adolescent↗

PubMed2001

Maternal cannabis use in the sudden death syndrome.

The smoking of cannabis and tobacco is common in many countries. In contrast to tobacco, which is an established risk factor for the sudden infant death syndrome (SIDS), nothing is known about cannabis and its effects on SIDS risk. We analysed data collected in a nation-wide case control study in New Zealand (393 cases, 1592 controls) to determine if there is any association between maternal cannabis use and SIDS risk. Adjusting for ethnicity and maternal tobacco use, the SIDS odds ratio for >weekly maternal cannabis use since the infant's birth was 2.23 (95% CI = 1.39, 3.57) compared to non-users; and the multivariate odds ratio was 1.55 (95% CI = 0.87, 2.75). We conclude that frequent maternal cannabis use may be a weak risk factor for SIDS, but this finding requires further research.

Adult↗

PubMed2000

Audiological screening of neonatal intensive care unit graduates at high risk of sensorineural hearing loss.

AIM: To audit the identification and screening of graduates from a neonatal intensive care unit with risk factors for sensorineural hearing loss. METHODS: Hospital medical records of newborn infants discharged from the neonatal intensive care unit, Christchurch Womens Hospital, between 1 July 1994 and 30 June 1995 (n=564), were examined to identify those at risk for sensorineural hearing loss according to the American Speech-Language Hearing Association risk criteria 1991. Auditory brainstem response test results were obtained from the Christchurch Hospital Audiology Department. Outcome measures were: presence of hearing loss risk factors, numbers tested with auditory brainstem response, age at test and presence and degree of hearing impairment. RESULTS: Of 5,215 live births in Christchurch, 564 infants were discharged through the neonatal intensive care unit. Of these, 86 had risk factors for sensorineural hearing loss. There were 72 (84%) infants tested at audiology, with fifteen (17%) having abnormal test results. There were fourteen with risk factors who did not get audiology screening. CONCLUSION: A high proportion (84%) of high risk newborn infants had auditory brainstem response testing. Further improvement would require strict implementation of standard procedures. Auditory brainstem response screening is part of a wider population surveillance approach to identify hearing loss as early as possible.

Audiometry, Evoked Response↗

PubMed2000

Changes to infant sleep practices in Canterbury.

AIM: "Reducing the risk" is a public health primary initiative to minimise the incidence of Sudden Infant Death Syndrome (SIDS) in New Zealand. A number of SIDS risks relate to infant sleep practices. We describe current prevalences of these practices. METHODS: A cohort of Canterbury mothers delivering live infants during May 1997 (n = 411) were mailed a questionnaire in July surveying their infant's sleep practices. Survey results were compared to results derived from the Canterbury control infant component of the 1987-90 New Zealand Cot Death Study (NZCDS) (n = 174). Those mothers using either plastic or rubber mattress covers (n = 63) were issued a subsequent questionnaire pertaining to this mattress-wrapping practice. RESULTS: Completed questionnaires were returned by 274 (66.7%) mothers. Room sharing with mother was usual for 133 (48.5%) infants, no different from the 94 (54.0%) recorded in the NZCDS (chi 2 = 5.6, df = 2, p = 0.06). However, of those infants sharing a room with their mother, 101 (75.9%) slept in their own bed compared to 46 (48.9%) in the NZCDS (chi 2 = 57.0, df = 2, p < 0.01). Only 8 (2.9%) infants were regularly placed prone to sleep, considerably fewer than the 69 (39.7%) reported in the NZCDS (chi 2 = 100.1, df = 1, p < 0.01). Mattress-wrapping with plastic (14.6% vs. 4.0%; chi 2 = 12.8, df = 1, p < 0.01) and rubber (8.4% vs. 3.4%; chi 2 = 4.4, df = 1, p = 0.04) has significantly increased since the NZCDS. Results from the subsequent questionnaire, completed by 42 (66.7%) respondents, indicated that most, 25 (59.5%), wrapped their infant's mattress to stop soiling. Less than half, 18 (42.9%), wrapped the mattress for the "safety of their baby". CONCLUSION: The "non-prone sleeping" campaign has been successful in Canterbury. Most infants are now routinely placed non-prone for sleep. Of those infants sharing a room with their mothers, an increased proportion is sleeping in separate beds. The use of "drycot" under-blankets and sheepskins has diminished. While impermeable mattress-wrapping usage has significantly increased, over three-quarters of Canterbury mothers did not use plastic or rubber mattress-covers on their infant's beds.

Bedding and Linens↗

PubMed2000

The relationship between inside and outside ambient temperatures in Christchurch, New Zealand.

The objective of this study was to examine and identify relationships between hourly recorded meteorological temperature and ambient temperature, measured from within the home-sleeping environment of young infants' homes in Christchurch, New Zealand. From 1991 to 1994, home polysomnography recordings were conducted for up to 6 weeks on 32 infants aged between 2 and 24 weeks. One of the recorded signals was ambient room temperature. In total, 15735 hourly recordings of this temperature were available for analysis. The New Zealand Meteorological Service supplied hourly recordings of climatic temperature, collected over this time, from an exposed site that was considered to be representative of weather conditions for Christchurch. Temperature seasonality, hourly climatic temperature recordings and the interaction of these variables were found to be significantly related to the indoor ambient temperature recordings (all had P < 0.001). Fluctuations in hourly recorded indoor temperature appeared to lag outdoor temperature fluctuations by approximately 2 h; hence, a strong autocorrelation was identified in the regression residuals. The most parsimonious autoregression model accounted for 97% of the variability in the hourly indoor temperature measurements (r2 = 0.97). In Christchurch houses, which typically have poor thermal insulation properties, yet have no central heating capabilities, a very strong association between indoor and outdoor temperatures was clearly demonstrated.

Climate↗

PubMed2000

Weather and the risk of sudden infant death syndrome: the effect of wind.

STUDY OBJECTIVE: To examine and identify relations between sudden infant death syndrome (SIDS) and wind, particularly the föhn wind, in Christchurch, New Zealand. DESIGN: A retrospective epidemiological study combining details of regional hourly meteorological variables and reported SIDS cases. SETTING: Christchurch, New Zealand, between 1968 and 1997 inclusively. PARTICIPANTS: All 646 infants reported as dying from SIDS within the greater Christchurch region. MAIN RESULTS: Analysis of 1968-1989 data revealed nine wind variables significantly related to SIDS. When compared with corresponding variables calculated over the 1990-1997 period, only the northerly wind on the day of death and the southerly wind three days before a SIDS death had estimated associations with similar effect size and sign. However, both these variables had confidence intervals that included unity. CONCLUSIONS: No evidence was found to suspect that föhn winds influenced SIDS occurrence. The relations identified between SIDS incidence and wind, after controlling for the effects of temperature and trend, were tenuous and relatively small. More data are necessary to substantiate whether northerly winds on the day of death or southerly winds occurring three days before a death are truly associated with SIDS. It seems that wind has little, if any effect on SIDS incidence in Christchurch.

Atmosphere↗

PubMed1999

Water fluoridation and the sudden infant death syndrome.

AIMS: To determine whether exposure to fluoridated water supplies prenatally or postnatally at the time of death increases the risk of sudden infant death syndrome (SIDS). METHODS: A nationwide, case-control study, with infant's water fluoridation status determined from census area unit information for mother's usual address at the time of the infant's birth, infant's usual address at the time of death / nominated sleep and address where infant died / was at nominated sleep. SIDS risk associated with fluoride exposure postnatally was assessed according to method of infant feeding (breast or reconstituted formula), for the two days prior to infant's death / nominated sleep. RESULTS: Infants exposed to fluoridated water supplies during pregnancy were not at increased risk for SIDS, adjusted odds ratio (OR) 1.19 (95% confidence interval (CI) 0.82, 1.74). For breast-fed infants at the time of death / nominated sleep, fluoridated water exposure was not associated with an increased risk for SIDS, adjusted OR 1.09 (95% CI 0.66, 1.79). Similarly, 'fluoridated' formula feeding, when compared with 'unfluoridated' formula feeding, showed no increased risk of SIDS, adjusted OR 1.25 (95% CI 0.73, 2.13). There was no evidence of an interaction between fluoridation and infant feeding for the last two days (chi2 = 0.171, df = 1, p = 0.68). CONCLUSION: Exposure to a fluoridated water supply prenatally or postnatally at the time of death did not affect the relative risk for SIDS.

Analysis of Variance↗

PubMed1999

Deterministic properties of apnoeas in an abdominal breathing signal.

The paper describes a general set of properties that represent most apnoeas as found in an abdominal breathing signal. An apnoea is a pause in breathing during sleep, and only central apnoeas in infants are considered. Human experts are consulted to determine what properties of the signal they use to recognise apnoeas. A set of deterministic, or shape, properties is developed to represent expert opinion. An apnoea is modelled as a flat region with four properties: flatness, duration, thinness and smoothness. Mathematical descriptions of each property are formulated that discriminate between apnoea and non-apnoea events, and each description is tested for discrimination and independence. The average power of discrimination is 24% +/- 16% and the average correlation coefficient is 0.28 +/- 0.16. Applications include scoring apnoeas for sleep studies and developing standard definitions of apnoeas.

Algorithms↗

PubMed1999

Seasonal differences in risk factors for sudden infant death syndrome. The New Zealand Cot Death Study Group.

The aim of this study was to explore whether the risk of sudden infant death syndrome (SIDS) associated with prone sleeping position and other risk factors varies with season. The study was a large nation-wide case-control study, which compared 485 cases with 1800 controls. Parents of 393 (81.0%) cases and 1591 (88.4%) controls were interviewed. Obstetric records were also examined. Infants dying in winter were older and had lower birthweights than those dying in summer. The increased risk of SIDS associated with prone sleeping position was greater in winter than in summer. In contrast, the increased risk of SIDS associated with excess thermal insulation and bed sharing was less in winter than in summer. Prone sleeping position accounts for about half of the difference between the mortality rate in summer and that in winter. This suggests that some factor related to season modifies the effect of prone sleeping position.

Age Distribution↗

PubMed1999

Factor VIII, von Willebrand factor and the risk of major ischaemic heart disease in the Caerphilly Heart Study.

The relationships of three measurements of the factor VIII/von Willebrand factor (VWF) complex (factor VIII activity, FVIIIc (one-stage assay); VWF antigen, VWF Ag (ELISA); and VWF activity, VWF act, measured by a recently-developed ELISA) to major ischaemic heart disease (IHD) events were studied in 1997 men aged 49-65 years, in the second phase of the Caerphilly Heart Study. These variables were related using logistic regression analysis to myocardial infarction or IHD death, which occurred in 129 men during an average follow-up period of 61 months. All three measurements were highly correlated (r = 0.63-0.77), and each was significantly associated with incident major IHD on univariate analyses (relative odds in highest fifth compared to lowest fifth, 1.68-1.90; P = 0.028-0.006) and on multivariate analyses adjusting for major IHD risk factors and for baseline IHD. Neither FVIIIc nor VWF act was significantly related to incident IHD following adjustment for VWF Ag. We therefore suggest that the associations between these three measurements of the factor VIII/VWF complex and incident IHD might have at least three explanations: VWF Ag is a marker of arterial endothelial disturbance; VWF act promotes platelet adhesion/aggregation and hence the platelet component of arterial thrombosis; and FVIIIc promotes fibrin formation and hence the fibrin component of arterial thrombosis.

Enzyme-Linked Immunosorbent Assay↗

PubMed1998

Immunisation timeliness for a birth cohort in Christchurch. Christchurch Immunisation Coordination Study Group.

AIMS: To determine whether New Zealand's goals for immunisation coverage are being met in Christchurch and to assess whether scheduled vaccinations are being delivered in a timely fashion. METHODS: A cohort of all infants born in Christchurch during June, July and August 1995 were matched with immunisation benefit claim information for the 6-week, 3-month, 5-month and 15-month immunisation events. Those with incomplete reports were traced for amendment or verification of their immunisation status. RESULTS: The cohort contained 1002 infants. The full complement of scheduled immunisations was delivered to an estimated 95.8% (95% CI: 94.5, 97.2) of infants within the cohort by two years of age. Infants who presented late for their 6-week immunisation visits were significantly more likely to be late for their next visits (chi 2 log rank = 8.2, df = 1, p < 0.01), as were those late for their 3-month visits (chi 2 = 20.9, df = 1, p < 0.01), and their 5-month visits (chi 2 = 52.5, df = 1, p < 0.01). Infants were significantly less likely to receive their full complement of immunisations by two years of age if they presented late for their 6-week (Fisher's exact test, p = 0.01), 3-month (p < 0.01) or 5-month (p = 0.01) immunisation visits. CONCLUSIONS: The Immunisation 2000 target of 95% full immunisation coverage by two years of age was met by this cohort. However, infants who were late for any immunisation visits were more likely to be late for subsequent visits and incompletely vaccinated by two years of age, compared to those infants who presented on time.

Child, Preschool↗

PubMed1998

MMR immunisation coverage in Christchurch. Christchurch Immunisation Coordination Committee.

AIM: To measure measles-mumps-rubella (MMR) immunisation status of a birth cohort at 18 months of age. METHOD: All children born in Christchurch in June, July and August 1995 who were alive at 18 months of age (n = 999), were matched with MMR immunisation benefit claims. Those not listed were traced. RESULT: The final immunisation coverage rate was estimated at 85%. CONCLUSION: An 85% coverage rate at 18 months fell well short of the Immunisation 2000 target of 95% coverage by two years of age.

Humans↗

PubMed1998

Risk factors for preterm birth: a New Zealand study.

AIM: To identify risk factors for preterm birth. METHODS: A cross sectional study. The study population was 1800 infants selected randomly from all babies born over a three-year period. Of these, 85 (4.8%) were classified preterm (less than 37 completed weeks gestation). Data were collected from obstetric records and parental interviews. RESULTS: Risk factors associated with an increased risk of preterm birth after controlling for potential confounders included smoking during pregnancy (adjusted relative risk (RR) = 2.7, 95% confidence interval (CI) = 1.3, 5.4), and multiple birth (adjusted RR = 48.8, 95% CI = 18.1, 131.4). Urinary tract infection was significant at the 7% level (adjusted RR = 2.3, 95% CI = 1.0, 5.6). Alcohol intake in third trimester was associated with a reduced risk of preterm birth (adjusted RR = 0.4, 95% CI = 0.2, 0.7). CONCLUSION: Maternal smoking and multiple births were the most important modifiable risk factors in this study for preterm birth and may contribute to 17% and 11% of preterm births respectively.

Cross-Sectional Studies↗

PubMed1998

Sheepskin bedding and the sudden infant death syndrome. New Zealand Cot Death Study Group.

We carried out a nationwide case-control study, comparing 393 case patients with sudden infant death syndrome (SIDS) with 1592 control subjects, in order to examine sheepskin bedding as a risk factor. Sheepskin use was similar for case patients and control subjects (both, 42%; adjusted odds ratio [OR] = 1.28; 95% CI = 0.92, 1.79). Sheepskin use among the control subjects was associated with socioeconomic advantage. The relative risk for SIDS with sheepskin use was significantly increased in the infants placed prone to sleep (adjusted OR = 1.70; 95% CI = 1.08, 2.67), but not for infants placed in the supine or lateral position (adjusted OR = 0.82; 95% CI = 0.45, 1.48). An interaction between sheepskin use and bed sharing was also found. Sheepskin use was associated with a decreased risk of SIDS among infants sharing beds (adjusted OR = 0.61; 95% CI = 0.38, 0.99), but an increased risk among infants not bed sharing (adjusted OR = 2.25; 95% CI = 1.32, 3.86). We conclude that if an infant needs to be placed prone to sleep for medical reasons, a sheepskin should not be used as underbedding. However, for infants placed supine to sleep, sheepskins are not associated with an increased risk of SIDS.

Animals↗

PubMed1998

Residential mobility and sudden infant death syndrome.

OBJECTIVE: To examine whether permanent domicile change of the mother, thence the infant, or temporary relocation of the infant away from his or her usual place of residence affects the risk of sudden infant death syndrome (SIDS). DESIGN: A case-control nation-wide epidemiological study. SETTING: New Zealand between the years 1987-90. PARTICIPANTS: From the 485 SIDS diagnoses over this time, parents of 393 (81%) SIDS infants consented to participate and these comprise the cases. Controls were selected by randomly sampling 1800 infants from all babies born over 78% of the country. Parents of 1592 (88%) control infants participated. RESULTS: Infants away from their usual address were 1.70 (95% CI: 1.09, 2.66) times more likely to die from SIDS than infants sleeping at home, after controlling for likely confounding factors. A partial explanation for this finding was that SIDS infants were less likely to have been mainly breast fed in the last two days and were less likely to have shared a room with at least one adult at the nominated sleep/death. Infants of mothers who shifted house after their birth, infants having mothers who shifted house within a year prior to the study interview date, and infants who slept at numerous different houses were associated with an increased relative risk for SIDS at the univariate level, but not after adjustment. CONCLUSIONS: Infants are less likely to die in their accustomed residential environment. This finding needs confirmation by other studies.

Adult↗

PubMed1998

Changes in cotinine levels during pregnancy.

We measured maternal cotinine levels on residual sera of antenatal blood samples to biochemically document changes in smoking between early and late pregnancy. It was a random sample of 404 mothers who had both an early and late sample. Cotinine levels were used to categorize maternal smoking into nonsmoker (<15 ng/mL) and smoker (> or = 15 ng/mL) groups. Designated smokers were further partitioned into lighter (15-100 ng/mL) and heavier (>100 ng/mL) semiquantitative groupings. There was a positive cotinine result in 113 (28%) mothers in early pregnancy; of these smoking women, 35 (31%) had quit smoking by the time of their late pregnancy blood test and 28 (25%) had reduced their cotinine level by at least 25%. Many more lighter smokers had quit (59%) compared to heavier smokers (17%) (X2 = 20.9, df=1, p<0.001). By late pregnancy, 86 (21%) mothers were still defined as smokers. Almost 30% of pregnant women in this sample were smoking during early pregnancy declining to 21% in late pregnancy.

Cotinine↗

PubMed1998

Heavy caffeine intake in pregnancy and sudden infant death syndrome. New Zealand Cot Death Study Group.

AIMS: To examine the association between maternal caffeine consumption during pregnancy and the risk of sudden infant death syndrome (SIDS). METHODS: A nationwide case-control study surveying parents of 393 SIDS victims and parents of 1592 control infants. Caffeine consumption in each of the first and third trimesters was estimated by questionnaire. Heavy caffeine intake was defined as 400 mg/day or more (equivalent to four or more cups of coffee per day). RESULTS: Infants whose mothers had heavy caffeine consumption throughout their pregnancy had a significantly increased risk for SIDS (odds ratio 1.65; 95% confidence interval 1.15 to 2.35) after adjusting for likely confounding factors. CONCLUSION: Caffeine intake has been associated with fetal harm and now SIDS. Reducing heavy caffeine intake during pregnancy could be another way to lessen the risk of SIDS. This needs confirmation by others.

Caffeine↗