Thenmalar Vadiveloo

Reliability of self reported smoking status by pregnant women for estimating smoking prevalence: a retrospective, cross sectional study

Objective To determine what impact reliance on self reported smoking status during pregnancy has on both the accuracy of smoking prevalence figures and access to smoking cessation services for pregnant women in Scotland. Design Retrospective, cross sectional study of cotinine measurements in stored blood samples. Participants Random sample (n=3475) of the 21 029 pregnant women in the West of Scotland who opted for second trimester prenatal screening over a one year period. Main outcome measure Smoking status validated with cotinine measurement by maternal area deprivation category (Scottish Index of Multiple Deprivation). Results Reliance on self reported smoking status underestimated true smoking by 25% (1046/3475 (30%) from cotinine measurement v 839/3475 (24%) from self reporting, z score 8.27, P<0.001). Projected figures suggest that in Scotland more than 2400 pregnant smokers go undetected each year. A greater proportion of smokers in the least deprived areas (deprivation categories 1+2) did not report their smoking (39%) compared with women in the most deprived areas (22% in deprivation categories 4+5), but, because smoking was far more common in the most deprived areas (706 (40%) in deprived areas compared with 142 (14%) in affluent areas), projected figures for Scotland suggest that twice as many women in the most deprived areas are undetected (n=1196) than in the least deprived areas (n=642). Conclusion Reliance on self reporting to identify pregnant smokers significantly underestimates the number of pregnant smokers in Scotland and results in a failure to detect over 2400 smokers each year who are therefore not offered smoking cessation services.

The Thyroid Epidemiology, Audit, and Research Study (TEARS): Morbidity in Patients with Endogenous Subclinical Hyperthyroidism

OBJECTIVE Our objective was to investigate the long-term outcomes for patients with endogenous subclinical hyperthyroidism (SH). DESIGN Population record-linkage technology was used retrospectively to identify patients with SH and hospital admissions from January 1, 1993, to December 31, 2009. PATIENTS All Tayside residents over 18 yr old with at least two serum TSH measurements below the reference range for at least 4 months apart and normal free T(4)/total T(4) and normal total T(3) concentrations at baseline were included as potential cases. Using a unique patient identifier, data linkage enabled a cohort of SH cases to be identified from biochemistry, prescription, admission, and radioactive iodine treatment records matched to five comparators from the general population. OUTCOME MEASURES The association between endogenous SH and cardiovascular disease, fracture, dysrhythmia, dementia, and cancer was assessed. RESULTS Compared with the reference population, SH was associated with an increased risk of nonfatal cardiovascular morbidity, osteoporotic fracture, dysrhythmia, and dementia, with adjusted hazard ratios (HR) of 1.39 (1.22-1.58), 1.25 (1.04-1.50), 1.65 (1.26-2.17), and 1.64 (1.20-2.25), respectively. When SH patients who developed overt hyperthyroidism during follow-up were excluded, SH patients were associated with an increased risk of cardiovascular morbidity [HR = 1.36 (1.19-1.57)], dysrhythmia [HR = 1.39 (1.02-1.90)], and dementia [HR = 1.79 (1.28-2.51)] but not fracture and cancer. CONCLUSION Patients with endogenous SH have an increased risk of cardiovascular disease and dysrhythmia. There is an association with fracture and dementia that is not related to TSH concentration and therefore is less likely to be causally related. No association was found between SH and cancer.

The Thyroid Epidemiology, Audit, and Research Study (TEARS): the natural history of endogenous subclinical hyperthyroidism.

OBJECTIVE For patients with subclinical hyperthyroidism (SH), the objective of the study was to define the rates of progression to frank hyperthyroidism and normal thyroid function. DESIGN Record-linkage technology was used retrospectively to identify patients with SH in the general population of Tayside, Scotland, from January 1, 1993, to December 31, 2009. PATIENTS All Tayside residents with at least two measurements of TSH below the reference range for at least 4 months from baseline and normal free T(4)/total T(4) and total T(3) concentrations at baseline were included as potential cases. Using a unique patient identifier, data linkage enabled a cohort of SH cases to be identified from prescription, admission, and radioactive iodine treatment records. Cases younger than 18 yr of age were also excluded from the study. OUTCOME MEASURES The status of patients was investigated at 2, 5, and 7 yr after diagnosis. RESULTS We identified 2024 cases with SH, a prevalence of 0.63% and an incidence of 29 per 100,000 in 2008. Most SH cases without thyroid treatment remained as SH at 2 (81.8%), 5 (67.5%), and 7 yr (63.0%) after diagnosis. Few patients (0.5-0.7%) developed hyperthyroidism at 2, 5, and 7 yr. The percentage of SH cases reverting to normal increased with time: 17.2% (2 yr), 31.5% (5 yr), and 35.6% (7 yr), and this was more common in SH patients with baseline TSH between 0.1 and 0.4 mU/liter. CONCLUSION Very few SH patients develop frank hyperthyroidism, whereas a much larger proportion revert to normal, and many remain with SH.

Risk of AKI with Gentamicin as Surgical Prophylaxis

In 2009, the Scottish government issued a target to reduce Clostridium difficile infection by 30% in 2 years. Consequently, Scottish hospitals changed from cephalosporins to gentamicin for surgical antibiotic prophylaxis. This study examined rates of postoperative AKI before and after this policy change. The study population comprised 12,482 adults undergoing surgery (orthopedic, urology, vascular, gastrointestinal, and gynecology) with antibiotic prophylaxis between October 1, 2006, and September 30, 2010 in the Tayside region of Scotland. Postoperative AKI was defined by the Kidney Disease Improving Global Outcomes criteria. The study design was an interrupted time series with segmented regression analysis. In orthopedic patients, change in policy from cefuroxime to flucloxacillin (two doses of 1 g) and single-dose gentamicin (4 mg/kg) was associated with a 94% increase in AKI (P=0.04; 95% confidence interval, 93.8% to 94.3%). Most patients who developed AKI after prophylactic gentamicin had stage 1 AKI, but some patients developed persistent stage 2 or stage 3 AKI. The antibiotic policy change was not associated with a significant increase in AKI in the other groups. Regardless of antibiotic regimen, however, rates of AKI were high (24%) after vascular surgery, and increased steadily after gastrointestinal surgery. Rates could only be ascertained in 52% of urology patients and 47% of gynecology patients because of a lack of creatinine testing. These results suggest that gentamicin should be avoided in orthopedic patients in the perioperative period. Our findings also raise concerns about the increasing prevalence of postoperative AKI and failures to consistently measure postoperative renal function.

Social, environmental and psychological factors associated with objective physical activity levels in the over 65s.

Objective To assess physical activity levels objectively using accelerometers in community dwelling over 65 s and to examine associations with health, social, environmental and psychological factors. Design Cross sectional survey. Setting 17 general practices in Scotland, United Kingdom. Participants Random sampling of over 65 s registered with the practices in four strata young-old (65–80 years), old-old (over 80 years), more affluent and less affluent groups. Main Outcome Measures Accelerometry counts of activity per day. Associations between activity and Theory of Planned Behaviour variables, the physical environment, health, wellbeing and demographic variables were examined with multiple regression analysis and multilevel modelling. Results 547 older people (mean (SD) age 79(8) years, 54% female) were analysed representing 94% of those surveyed. Accelerometry counts were highest in the affluent younger group, followed by the deprived younger group, with lowest levels in the deprived over 80 s group. Multiple regression analysis showed that lower age, higher perceived behavioural control, the physical function subscale of SF-36, and having someone nearby to turn to were all independently associated with higher physical activity levels (R2 = 0.32). In addition, hours of sunshine were independently significantly associated with greater physical activity in a multilevel model. Conclusions Other than age and hours of sunlight, the variables identified are modifiable, and provide a strong basis for the future development of novel multidimensional interventions aimed at increasing activity participation in later life.

Risk of postoperative acute kidney injury in patients undergoing orthopaedic surgery--development and validation of a risk score and effect of acute kidney injury on survival: observational cohort study.

Study question What is the predicted risk of acute kidney injury after orthopaedic surgery and does it affect short term and long term survival? Methods The cohort comprised adults resident in the National Health Service Tayside region of Scotland who underwent orthopaedic surgery from 1 January 2005 to 31 December 2011. The model was developed in 6220 patients (two hospitals) and externally validated in 4395 patients from a third hospital. Several preoperative variables were selected for candidate predictors, based on literature, clinical expertise, and availability in the orthopaedic surgery setting. The main outcomes were the development of any severity of acute kidney injury (stages 1-3) within the first postoperative week, and 90 day, one year, and longer term survival. Study answer and limitations Using logistic regression analysis, independent predictors of acute kidney injury were older age, male sex, diabetes, number of prescribed drugs, lower estimated glomerular filtration rate, use of angiotensin converting enzyme inhibitors or angiotensin receptor blockers, and American Society of Anesthesiologists grade. The model’s predictive performance for discrimination was good (C statistic 0.74 in development cohort, 0.70 in validation cohort). Calibration was good in the development cohort and after recalibration in the validation cohort. Only the highest risks were over-predicted. Survival was worse in patients with acute kidney injury compared with those without (adjusted hazard ratio 1.53, 95% confidence interval 1.38 to 1.70). This was most noticeable in the short term (adjusted hazard ratio: 90 day 2.36, 1.94 to 2.87) and diminished over time (90 day-one year 1.40, 1.10 to 1.79; >1 year 1.28, 1.10 to 1.48). The model used routinely collected data in the orthopaedic surgery setting therefore some variables that could potentially improve predictive performance were not available. However, the readily available predictors make the model easily applicable. What this study adds A preoperative risk prediction model consisting of seven predictors for acute kidney injury was developed, with good predictive performance in patients undergoing orthopaedic surgery. Survival was significantly poorer in patients even with mild (stage 1) postoperative acute kidney injury. Funding, competing interests, data sharing SB received grants from Tenovus Tayside, Chief Scientist Office, and the Royal College of Physicians and Surgeons of Glasgow; PT receives grants from Novo Nordisk, GlaxoSmithKline, and the New Drugs Committee of the Scottish Medicines Consortium. No additional data are available.

Association of day length and weather conditions with physical activity levels in older community dwelling people.

Background Weather is a potentially important determinant of physical activity. Little work has been done examining the relationship between weather and physical activity, and potential modifiers of any relationship in older people. We therefore examined the relationship between weather and physical activity in a cohort of older community-dwelling people. Methods We analysed prospectively collected cross-sectional activity data from community-dwelling people aged 65 and over in the Physical Activity Cohort Scotland. We correlated seven day triaxial accelerometry data with daily weather data (temperature, day length, sunshine, snow, rain), and a series of potential effect modifiers were tested in mixed models: environmental variables (urban vs rural dwelling, percentage of green space), psychological variables (anxiety, depression, perceived behavioural control), social variables (number of close contacts) and health status measured using the SF-36 questionnaire. Results 547 participants, mean age 78.5 years, were included in this analysis. Higher minimum daily temperature and longer day length were associated with higher activity levels; these associations remained robust to adjustment for other significant associates of activity: age, perceived behavioural control, number of social contacts and physical function. Of the potential effect modifier variables, only urban vs rural dwelling and the SF-36 measure of social functioning enhanced the association between day length and activity; no variable modified the association between minimum temperature and activity. Conclusions In older community dwelling people, minimum temperature and day length were associated with objectively measured activity. There was little evidence for moderation of these associations through potentially modifiable health, environmental, social or psychological variables.

Drugs that interact with levothyroxine: an observational study from the Thyroid Epidemiology, Audit and Research Study (TEARS)

The aim of this study was to determine the extent of drug interactions affecting levothyroxine, using study drugs often co‐administered to patients on long‐term levothyroxine therapy.

Thyroid testing in pregnant women with thyroid dysfunction in Tayside, Scotland: the thyroid epidemiology, audit and research study (TEARS)

To investigate the rate of thyroid testing during pregnancy.

Dog ownership and physical activity in later life: A cross-sectional observational study

OBJECTIVE To examine whether dog ownership amongst community dwelling older adults (≥ 65 years) is associated with objectively measured physical activity (PA). METHODS We used data from the Physical Activity Cohort Scotland (PACS) which consists of 547 people aged 65 and over, resident in the community in Tayside, Scotland. The data was collected in 2009-2011. We assessed whether dog ownership is associated with objectively measured physical activity (accelerometry counts). RESULTS The physical activity (PA) counts of 547 older people (mean age 79 (standard deviation (SD) 8 years, 54% female) were analysed. Linear mixed models showed that dog ownership was positively related to higher PA levels. This positive relationship remained after controlling for a large number of individual and contextual variables, including attitude towards exercise, physical activity intention and history of physical activity. Dog owners were found to be 12% more active (21,875 counts, 95% Confidence Interval (CI): 2810 to 40,939, p<0.05) than non-dog owners. CONCLUSION Dog ownership is associated with physical activity in later life. Interventions to increase activity amongst older people might usefully attempt to replicate elements of the dog ownership experience.