Gail M. Williams

A systematic review of the global prevalence of low back pain

OBJECTIVE To perform a systematic review of the global prevalence of low back pain, and to examine the influence that case definition, prevalence period, and other variables have on prevalence. METHODS We conducted a new systematic review of the global prevalence of low back pain that included general population studies published between 1980 and 2009. A total of 165 studies from 54 countries were identified. Of these, 64% had been published since the last comparable review. RESULTS Low back pain was shown to be a major problem throughout the world, with the highest prevalence among female individuals and those aged 40-80 years. After adjusting for methodologic variation, the mean ± SEM point prevalence was estimated to be 11.9 ± 2.0%, and the 1-month prevalence was estimated to be 23.2 ± 2.9%. CONCLUSION As the population ages, the global number of individuals with low back pain is likely to increase substantially over the coming decades. Investigators are encouraged to adopt recent recommendations for a standard definition of low back pain and to consult a recently developed tool for assessing the risk of bias of prevalence studies.

Daily sunscreen application and betacarotene supplementation in prevention of basal-cell and squamous-cell carcinomas of the skin: a randomised controlled trial

BACKGROUND The use of sunscreens on the skin can prevent sunburn but whether long-term use can prevent skin cancer is not known. Also, there is evidence that oral betacarotene supplementation lowers skin-cancer rates in animals, but there is limited evidence of its effect in human beings. METHODS In a community-based randomised trial with a 2 by 2 factorial design, individuals were assigned to four treatment groups: daily application of a sun protection factor 15-plus sunscreen to the head, neck, arms, and hands, and betacarotene supplementation (30 mg per day); sunscreen plus placebo tablets; betacarotene only; or placebo only. Participants were 1621 residents of Nambour in southeast Queensland, Australia. The endpoints after 4.5 years of follow-up were the incidence of basal-cell and squamous-cell carcinomas both in terms of people treated for newly diagnosed disease and in terms of the numbers of tumours that occurred. Analysis of the effect of sunscreen was based only on skin cancers that developed on sites of daily application. All analyses were by intention to treat. FINDINGS 1383 participants underwent full skin examination by a dermatologist in the follow-up period. 250 of them developed 758 new skin cancers during the follow-up period. There were no significant differences in the incidence of first new skin cancers between groups randomly assigned daily sunscreen and no daily sunscreen (basal-cell carcinoma 2588 vs 2509 per 100,000; rate ratio 1.03 [95% CI 0.73-1.46]; squamous-cell carcinoma 876 vs 996 per 100,000; rate ratio 0.88 [0.50-1.56]). Similarly, there was no significant difference between the betacarotene and placebo groups in incidence of either cancer (basal-cell carcinoma 3954 vs 3806 per 100,000; 1.04 [0.73-1.27]; squamous-cell carcinoma 1508 vs 1146 per 100,000; 1.35 [0.84-2.19]). In terms of the number of tumours, there was no effect on incidence of basal-cell carcinoma by sunscreen use or by betacarotene but the incidence of squamous-cell carcinoma was significantly lower in the sunscreen group than in the no daily sunscreen group (1115 vs 1832 per 100,000; 0.61 [0.46-0.81]). INTERPRETATION There was no harmful effect of daily use of sunscreen in this medium-term study. Cutaneous squamous-cell carcinoma, but not basal-cell carcinoma seems to be amenable to prevention through the routine use of sunscreen by adults for 4.5 years. There was no beneficial or harmful effect on the rates of either type of skin cancer, as a result of betacarotene supplementation.

The global burden of low back pain: estimates from the Global Burden of Disease 2010 study

Objective To estimate the global burden of low back pain (LBP). Methods LBP was defined as pain in the area on the posterior aspect of the body from the lower margin of the twelfth ribs to the lower glutaeal folds with or without pain referred into one or both lower limbs that lasts for at least one day. Systematic reviews were performed of the prevalence, incidence, remission, duration, and mortality risk of LBP. Four levels of severity were identified for LBP with and without leg pain, each with their own disability weights. The disability weights were applied to prevalence values to derive the overall disability of LBP expressed as years lived with disability (YLDs). As there is no mortality from LBP, YLDs are the same as disability-adjusted life years (DALYs). Results Out of all 291 conditions studied in the Global Burden of Disease 2010 Study, LBP ranked highest in terms of disability (YLDs), and sixth in terms of overall burden (DALYs). The global point prevalence of LBP was 9.4% (95% CI 9.0 to 9.8). DALYs increased from 58.2 million (M) (95% CI 39.9M to 78.1M) in 1990 to 83.0M (95% CI 56.6M to 111.9M) in 2010. Prevalence and burden increased with age. Conclusions LBP causes more global disability than any other condition. With the ageing population, there is an urgent need for further research to better understand LBP across different settings.

Reduced Melanoma After Regular Sunscreen Use: Randomized Trial Follow-Up

PURPOSE Regular sunscreen use prevents cutaneous squamous cell carcinoma long term, but the effect on melanoma is highly controversial. We evaluated whether long-term application of sunscreen decreases risk of cutaneous melanoma. PARTICIPANTS AND METHODS In 1992, 1,621 randomly selected residents of Nambour, a township in Queensland, Australia, age 25 to 75 years, were randomly assigned to daily or discretionary sunscreen application to head and arms in combination with 30 mg beta carotene or placebo supplements until 1996. Participants were observed until 2006 with questionnaires and/or through pathology laboratories and the cancer registry to ascertain primary melanoma occurrence. RESULTS Ten years after trial cessation, 11 new primary melanomas had been identified in the daily sunscreen group, and 22 had been identified in the discretionary group, which represented a reduction of the observed rate in those randomly assigned to daily sunscreen use (hazard ratio [HR], 0.50; 95% CI, 0.24 to 1.02; P = .051). The reduction in invasive melanomas was substantial (n = 3 in active v 11 in control group; HR, 0.27; 95% CI, 0.08 to 0.97) compared with that for preinvasive melanomas (HR, 0.73; 95% CI, 0.29 to 1.81). CONCLUSION Melanoma may be preventable by regular sunscreen use in adults.

Chronicity, Severity, and Timing of Maternal Depressive Symptoms: Relationships with Child Outcomes at Age 5.

The relationships between severity, chronicity, and timing of maternal depressive symptoms and child outcomes were examined in a cohort of 4,953 children. Mothers provided self-reports of depressive symptoms during pregnancy, immediately postpartum, and when the child was 6 months old and 5 years old. At the age 5 follow-up, mothers reported on childrens behavior and children completed a receptive vocabulary test. Results suggest that both the severity and the chronicity of maternal depressive symptoms are related to more behavior problems and lower vocabulary scores in children. The interaction of severity and chronicity of maternal depressive symptoms was significantly related to higher levels of child behavior problems. Timing of maternal symptoms was not significantly related to child vocabulary scores, but more recent reports of maternal depressive symptoms were associated with higher rates of child behavior problems.

Schistosomiasis in the People's Republic of China: Prospects and Challenges for the 21st Century

SUMMARY Schistosomiasis japonica is a serious communicable disease and a major disease risk for more than 30 million people living in the tropical and subtropical zones of China. Infection remains a major public health concern despite 45 years of intensive control efforts. It is estimated that 865,000 people and 100,250 bovines are today infected in the provinces where the disease is endemic, and its transmission continues. Unlike the other schistosome species known to infect humans, the oriental schistosome, Schistosoma japonicum, is a true zoonotic organism, with a range of mammalian reservoirs, making control efforts extremely difficult. Clinical features of schistosomiasis range from fever, headache, and lethargy to severe fibro-obstructive pathology leading to portal hypertension, ascites, and hepatosplenomegaly, which can cause premature death. Infected children are stunted and have cognitive defects impairing memory and learning ability. Current control programs are heavily based on community chemotherapy with a single dose of the drug praziquantel, but vaccines (for use in bovines and humans) in combination with other control strategies are needed to make elimination of the disease possible. In this article, we provide an overview of the biology, epidemiology, clinical features, and prospects for control of oriental schistosomiasis in the Peoples Republic of China.

Associations of Gestational Weight Gain With Offspring Body Mass Index and Blood Pressure at 21 Years of Age Evidence From a Birth Cohort Study

Background— Maternal weight gain in pregnancy is positively associated with offspring body mass index (BMI) and obesity risk in childhood, but whether this increased risk extends into adulthood or results in increases in other cardiovascular risk factors such as elevated blood pressure (BP) is unclear. Methods and Results— We used a population-based birth cohort of 2432 individuals (50% male) born in Brisbane, Australia, between 1981 and 1983 to prospectively examine the association between maternal gestational weight gain (GWG) and offspring BMI and BP at 21 years. On average, each mother gained 14.8 kg (SD, 5.1 kg) during her pregnancy. At 21 years of age, offspring mean BMI, systolic BP, and diastolic BP were 24.2 kg/m2 (SD, 4.9 kg/m2), 116.4 mm Hg (SD, 14.5 mm Hg), and 67.7 mm Hg (SD, 8.5 mm Hg), respectively. Offspring BMI was on average 0.3 kg/m2 (95% confidence interval, 0.1 to 0.4 kg/m2) higher for each 0.1-kg/wk greater GWG after adjustment for potential confounding factors. Systolic BP also was greater (0.2 mm Hg per 0.1 kg; 95% confidence interval, −0.2 to 0.6) in offspring whose mothers had higher GWG. Although this association was not statistically significant, it was consistent in magnitude with the association of maternal GWG with offspring BMI and of offspring BMI with BP. Conclusions— Our findings show that greater GWG is associated with greater offspring BMI into early adulthood and that this may translate into higher systolic BP in offspring. Further large studies are required to confirm an effect of GWG on a range of offspring cardiovascular risk factors.

Prolonged Prevention of Squamous Cell Carcinoma of the Skin by Regular Sunscreen Use

Half of all cancers in the United States are skin cancers. We have previously shown in a 4.5-year randomized controlled trial in an Australian community that squamous cell carcinomas (SCC) but not basal cell carcinomas (BCC) can be prevented by regular sunscreen application to the head, neck, hands, and forearms. Since cessation of the trial, we have followed participants for a further 8 years to evaluate possible latency of preventive effect on BCCs and SCCs. After prolonged follow-up, BCC tumor rates tended to decrease but not significantly in people formerly randomized to daily sunscreen use compared with those not applying sunscreen daily. By contrast, corresponding SCC tumor rates were significantly decreased by almost 40% during the entire follow-up period (rate ratio, 0.62; 95% confidence interval, 0.38-0.99). Regular application of sunscreen has prolonged preventive effects on SCC but with no clear benefit in reducing BCC. (Cancer Epidemiol Biomarkers Prev 2006;15(12):2546–8)

Cohort Profile Update: The Mater-University of Queensland Study of Pregnancy (MUSP)

The Mater-University of Queensland Study of Pregnancy (MUSP) and its outcomes began in 1981 with data collected on 7223 pregnant woman-child pairs (6753 mothers, of whom 520 had 2 study children, less 50 who had multiple births). These women, and their children, were initially followed for up to 21 years. Since then there have been additional follow-ups of the mothers (27 years) and their children (30 years). There has also been a substantial increase in the breadth of topics addressed, with the collection of biological samples, the administration of structured clinical assessments of mental health and cognitive capacity, and markers of physical health such as lung function and blood pressure. MUSP was originally developed as a birth cohort study. It has become a longitudinal study of growth, development and ageing with an emphasis on the generational transmission of a wide range of factors impacting on adult health outcomes. We welcome interest in our study; for study background and publications visit [www.socialscience.uq.edu.au/musp] or contact [j.najman@uq.edu.au].

Associations of Parental, Birth, and Early Life Characteristics With Systolic Blood Pressure at 5 Years of Age Findings From the Mater-University Study of Pregnancy and Its Outcomes

Background—We examined the associations of a range of parental and early life characteristics with systolic blood pressure at 5 years of age. Methods and Results—Information from 3864 children who were followed up prospectively from their mother’s first antenatal clinic assessment was used. Maternal age, body mass index, and smoking during pregnancy were all positively associated with offspring systolic blood pressure at 5 years of age. The systolic blood pressure of children whose mothers had smoked throughout pregnancy was on average 0.92 mm Hg (95% CI 0.17 to 1.68) greater than that of children whose mothers had never smoked, after full adjustment. Children who had been breast fed until at least 6 months had lower systolic blood pressure than those who were breast fed for a shorter duration. Paternal body mass index and child’s weight, height, and body mass index were all positively associated with blood pressure at age 5. Conclusions—Because childhood blood pressure tracks into adulthood, interventions aimed at early life risk factors, such as quitting smoking during pregnancy, breast feeding, and prevention of obesity in all family members, may be important for reducing the population distribution of blood pressure and thus cardiovascular disease risk.