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Biomedical subjects

L Smeeth

Publications and source records attributed to L Smeeth.

At least 19 recordsLinked to original sources
PubMed2007

Standardized training for healthcare professionals and its impact on patients with perennial rhinitis: a multi-centre randomized controlled trial.

BACKGROUND: Perennial rhinitis is common and often results in substantial, potentially avoidable, impairment of quality of life. Quality of rhinitis care has been shown to be sub-optimal in general practice. Rigorous evaluation of educational interventions for healthcare professionals using randomized controlled trials is very uncommon. OBJECTIVE: To evaluate the effectiveness of standardized allergy training for healthcare professionals on patients' disease-specific quality of life. METHODS: Patients with clinician diagnosed perennial rhinitis and/or a prescription for relevant nasal medication were recruited from general practice. Following baseline measurement of quality of life using the validated rhino-conjunctivitis questionnaire (RQLQ), patients were centrally randomized to receive care from an allergy-trained primary healthcare professional or routine care. RQLQ was measured again at 13 months after randomization. RESULTS: Process measures revealed that the training was well received. 202 patients were included in the intention-to-treat analysis and 157 in the per-protocol analysis. There was a 0.23 greater mean improvement in quality-of-life scores in the intervention group when compared with controls (P=0.08) in the intention-to-treat analysis, this increasing to a 0.3 greater mean improvement if confined to a per-protocol analysis (P=0.05). The intention-to-treat analysis showed that 39/101 (39%) in the intervention group showed a clinically significant > or =0.5 improvement in RQLQ compared with 28/101 (28%) of controls (risk difference=11%, number needed to treat=9, P=0.1). CONCLUSIONS: Standardized allergy education given to primary healthcare professionals leads to modest improvements in disease-specific quality of life in patients with perennial rhinitis.

Adult↗
PubMed2006

Community screening for visual impairment in the elderly.

BACKGROUND: While the aims of multicomponent screening of older people are broad, any benefit arising from the inclusion of a vision component in the assessment will necessarily be dependent on improving vision. OBJECTIVES: To assess the effects on vision of mass screening of older people for visual impairment. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Group Trials Register, in The Cochrane Library (Issue 1, 2006), NRR (Issue 1, 2006), MEDLINE (1966 to February 2006), EMBASE (1980 to February 2006), PubMed (on 8th March; last 90 days), SciSearch and reference lists of relevant trial reports and review articles. We contacted investigators to identify additional published and unpublished trials. SELECTION CRITERIA: We included randomised trials of visual or multicomponent screening for identifying vision impairment in people aged 65 years or over in a community setting. DATA COLLECTION AND ANALYSIS: Both authors independently extracted data and assessed trial quality. MAIN RESULTS: Visual outcome data were available for 3494 people in five trials of multicomponent assessment. Length of follow up ranged from two to four years. All the trials used self-reported measures for visual impairment, both as screening tools and as outcome measures. In four of the trials people reporting visual problems were referred to either eye services or a physician. In one trial people reporting visual problems received information about resources in the community designed to assist those with poor vision. The proportions of participants in the intervention and control groups who reported visual problems at the time of outcome assessment were 0.26 and 0.23 respectively (risk ratio for visual impairment 1.03, 95% confidence interval (CI) 0.92 to 1.15). Visual outcome data were also available for 1807 people aged 75 years and over in a cluster randomised trial in which physicians' general practices were randomised to two different screening strategies; universal or targeted. Three to five years after screening, the risk ratio for visual acuity less than 6/18 in either eye comparing universal with targeted screening was 1.07 (95% CI 0.84 to 1.36, P = 0.58). The mean composite score of the National Eye Institute 25 item visual function questionnaire was 85.6 in the targeted screening group and 86.0 in the universal group, a difference of 0.4 (95% CI -1.7 to 2.5, P = 0.69). AUTHORS' CONCLUSIONS: There is no evidence that community-based screening of asymptomatic older people results in improvements in vision.

Aged↗
PubMed2006

Incidence of diagnosed polymyalgia rheumatica and temporal arteritis in the United Kingdom, 1990-2001.

OBJECTIVE: To investigate time trends, geographical variation, and seasonality in the incidence of diagnosis of polymyalgia rheumatica (PMR) and temporal arteritis (TA) in the United Kingdom. METHODS: Analysis of computerised medical records from UK general practices. Participants were registered with a practice contributing to the General Practice Research Database during the period 1990-2001. The main outcome measures were rates of diagnosis by year, age, sex, geographical region, and calendar month. RESULTS: 15 013 people had a first diagnosis of PMR and 3928 a first diagnosis of TA during 17 830 028 person-years of observation. The age adjusted incidence rate of PMR was 8.4/10 000 person-years (95% CI 8.3 to 8.6), rising from 6.9/10 000 person-years in 1990 to 9.3/10 000 in 2001. The age adjusted incidence rate of TA was 2.2/10 000 person-years (95% CI 2.1 to 2.3) with no increase observed. Both PMR and TA were more common in the south than in the north of the UK, and both were more commonly diagnosed in the summer months. CONCLUSIONS: The explanation for the findings is unclear. Variations in diagnostic practice and accuracy are likely to have contributed in part to the patterns seen. However, the findings are also likely to reflect, at least in part, variations in the incidence of disease. The striking geographical pattern may be partly attributable to a risk factor which is more prevalent in the south and east of the United Kingdom.

Adult↗
PubMed2006

Hormone replacement therapy and cataract: a population-based case-control study.

PURPOSE: Laboratory studies have suggested that hormone replacement therapy (HRT) may protect against the development of cataract, but epidemiological studies in humans have thus far been inconclusive. The aim of this study was to assess the association between hormone replacement therapy and cataract. METHODS: Population-based case-control study using data from the General Practice Research Database in the UK. Participants were 10 000 women aged 45 years and over with diagnosed cataract and 10 000 controls matched on age, general practice, and calendar period. RESULTS: The crude odds ratio for the association between cataract and ever-use of oestrogen-only hormone replacement therapy was 1.13 (95% CI 0.99-1.29). This reduced to 0.81 (95% CI 0.71-0.94) after adjustment for consultation rate. Similarly, the crude odds ratio for the association between cataract and ever-use of a formulation containing oestrogen and progestogen was 1.18 (95% CI 1.01-1.39), reducing to 0.86 (95% CI 0.72-1.02) after adjustment for consultation rate. CONCLUSIONS: Oestrogen-only and oestrogen-progestogen hormone replacement therapies are associated with a small reduced risk of cataract. This data adds to the growing body of evidence on the effects of HRT on health. All potential benefits and risks of this therapy should be taken into account when considering its use.

Aged↗
PubMed2005

Photodynamic therapy for neovascular age-related macular degeneration.

BACKGROUND: In neovascular age-related macular degeneration (AMD) new vessels grow under the retina distorting vision and leading to scarring. This is exacerbated if the blood vessels leak. Photodynamic therapy (PDT) has been investigated as a way to treat the neovascular membranes without affecting the retina. OBJECTIVES: The aim of this review was to examine the effects of PDT in the treatment of neovascular AMD. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which includes the Cochrane Eyes and Vision Group Trials Register) on The Cochrane Library (Issue 1, 2005), MEDLINE (1966 to January 2005), EMBASE (1980 to January 2005). We used the Science Citation Index to search for reports that cited relevant studies. We contacted experts in the field and searched the reference lists of relevant studies. SELECTION CRITERIA: We included randomised trials of PDT in people with choroidal neovascularisation due to AMD. DATA COLLECTION AND ANALYSIS: Two authors independently extracted the data. Relative risks were combined using a fixed-effect model after testing for heterogeneity. MAIN RESULTS: Two published trials were identified that randomised 948 participants to verteporfin therapy compared to 5% dextrose in water. Both trials were performed by the same investigators using largely the same clinical centres and funded by manufacturers of verteporfin. Outcome data were available at 12 and 24 months after the first treatment. Participants received on average five treatments over two years. The relative risk of losing three or more lines of visual acuity at 24 months comparing the intervention with the control group was 0.77 (95% confidence interval 0.69 to 0.87). The relative risk of losing six or more lines of visual acuity at 24 months comparing the intervention with the control group was 0.62 (95% confidence interval 0.50 to 0.76). The results at 12 months were similar to those at 24 months. The most serious adverse outcome, acute (within 7 days of treatment) severe visual acuity decrease, occurs in about one in 50 patients. AUTHORS' CONCLUSIONS: Photodynamic therapy in people with choroidal neovascularisation due to AMD is probably effective in preventing visual loss though there is doubt about the size of the effect. Outcomes and potential adverse effects of this treatment should be monitored closely. Further independent trials of verteporfin are required to establish that the effects seen in this study are consistent and to examine important issues not yet addressed, particularly relating to quality of life and cost.

Glucose↗
PubMed2005

Does concurrent prescription of selective serotonin reuptake inhibitors and non-steroidal anti-inflammatory drugs substantially increase the risk of upper gastrointestinal bleeding?

BACKGROUND: A 15-fold increased risk of gastrointestinal bleeding has been reported with concurrent use of selective serotonin reuptake inhibitors and non-steroidal anti-inflammatory drugs. Recent guidance cautions against concurrent prescription, particularly in older people. AIM: To quantify the risk of gastrointestinal bleeding associated with current exposure to non-steroidal anti-inflammatory drugs, selective serotonin reuptake inhibitors, and both drugs concurrently. METHODS: We conducted a case-control analysis of 11,261 cases with upper gastrointestinal bleeding and 53,156 controls matched by gender, age and general practice from computerized primary care data. We coupled this with self-controlled case series analysis. RESULTS: Both drugs were associated with a twofold increased risk of gastrointestinal bleeding (odds ratio =2.38, 95% confidence interval 2.08-2.72 for selective serotonin reuptake inhibitors and odds ratio = 2.15, 95% confidence interval 2.02-2.28 for non-steroidal anti-inflammatory drugs). This increased risk was marginally higher for concurrent prescription (odds ratio = 2.93, 95% confidence interval 2.25-3.82). The self-controlled analysis showed a greater incidence rate ratio for gastrointestinal bleeding with non-steroidal anti-inflammatory drugs (2.71, 95% confidence interval 2.51-2.91) and lower incidence rate ratio with selective serotonin reuptake inhibitors (1.71, 95% confidence interval 1.48-1.98). The incidence rate ratio when both drugs were combined was 3.25, 95% confidence interval 1.95-5.42. Estimates were similar after restricting to people over 80 years of age. Increased risk of gastrointestinal bleeding was not specifically related to class of non-steroidal anti-inflammatory drugs and was similar when we looked at tricyclic anti-depressants. CONCLUSIONS: Our study suggests that the risk of gastrointestinal bleeding is not substantially increased when non-steroidal anti-inflammatory drugs and selective serotonin reuptake inhibitors are prescribed together, compared with their use alone.

Adult↗
PubMed2005

Bupropion and the risk of sudden death: a self-controlled case-series analysis using The Health Improvement Network.

BACKGROUND: Bupropion is an effective smoking cessation therapy but its use in the UK has been limited by concerns that it may increase the risk of sudden death. METHODS: Data for all patients prescribed bupropion within The Health Improvement Network (a computerised general practice database) were extracted and the self-controlled case-series method was used to estimate the relative incidence of death during the first 28 days of treatment. The incidence of seizures, a recognised adverse effect of bupropion, was also investigated during this period. RESULTS: A total of 9329 individuals had been prescribed bupropion (mean age 44 years, 48% male). The total person-time after the first prescription for bupropion was 17,586 years, and during this time 121 people died. Two people died within the first 28 days of treatment, which was less than expected in comparison with the remaining observation period by an incidence ratio of 0.50 (95% confidence interval (CI) 0.12 to 2.05). Twenty eight people were recorded as having a total of 45 seizures (23 before starting bupropion, two in the first 28 days of treatment, and 20 at a later point). The relative incidence of seizures during the first 28 days of treatment was 3.62 (95% CI 0.87 to 15.09), equivalent to one additional seizure per 6219 first time bupropion users. CONCLUSIONS: Bupropion use is probably associated with an increased risk of seizures, but no evidence was found to suggest that the drug is associated with an increased risk of sudden death.

Antidepressive Agents, Second-Generation↗
PubMed2005

A case control study of age related macular degeneration and use of statins.

AIMS: Age related macular degeneration (AMD) is the leading cause of blindness in industrialised countries. Previous studies have suggested that statins may have a protective effect against the disease; however, existing studies have had limited power to reliably detect or exclude an effect and have produced conflicting results. The authors assessed the risk of AMD associated with the use of statins. METHODS: Population based case control study using the United Kingdom General Practice Research Database. 18 007 people with diagnosed AMD were compared with 86 169 controls matched on age, sex, and general practice. The primary outcome was the odds ratio for the association between exposure to statins and AMD. RESULTS: The crude odds ratio for the association between any recorded exposure to statins and AMD was 1.32 (95% CI 1.17 to 1.48), but this reduced to 0.93 (95% CI 0.81 to 1.07, p=0.33) after adjustment for consultation rate, smoking, alcohol intake, body mass index, atherosclerotic disease, hyperlipidaemia, heart failure, diabetes mellitus, hypertension, use of other cardiovascular drugs, and use of fibrates. There was no evidence that the risk varied by dose of statin, duration of use, or that the risk varied for individual statins. CONCLUSION: In the short and medium term statin use is not associated with a decreased risk of AMD. Whether subgroups of patients with specific forms of AMD (particularly choroidal neovascularisation) benefit from statin therapy remains a possibility.

Aged↗
PubMed2005

General population based study of the impact of tricyclic and selective serotonin reuptake inhibitor antidepressants on the risk of acute myocardial infarction.

OBJECTIVE: To investigate the impact of tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) on the risk of first acute myocardial infarction (MI). DESIGN: Case-control analysis and a self controlled case series. SETTING: 644 general practices throughout England, Scotland, Wales, and Northern Ireland. PATIENTS: Over 60,000 cases of MI and 360,000 age, sex, and practice matched controls randomly selected from the UK General Practice Research Database. MAIN OUTCOME MEASURES: Matched odds ratios and incidence rate ratios estimating whether there is an acute or prolonged increased risk of MI after exposure to TCA and SSRI drugs and individual drugs within these families. RESULTS: Case-control analysis found an initial increased risk of MI after TCA exposure (for example, at 1-7 days after the first dothiepin prescription: odds ratio (OR) 1.90, 95% confidence interval (CI) 1.15 to 3.14) or SSRI exposure (for example, at 1-7 days after first fluoxetine prescription: OR 2.59, 95% CI 1.44 to 4.66). In the self controlled analysis the equivalent risk estimates were an incidence rate ratio of 1.43, 95% CI 0.92 to 2.22 for dothiepin and an incidence rate ratio of 1.66, 95% CI 1.01 to 2.71 for fluoxetine. CONCLUSIONS: Antidepressant prescriptions are associated with an increased risk of MI. The size of these effects is similar for TCA and SSRI exposures; however, the lack of specificity between types of antidepressants and the lower risks found in the self controlled analysis suggest that these associations are more likely due to factors relating to underlying depression and health services utilisation than to specific adverse drug effects.

Adult↗
PubMed2005

Use of nicotine replacement therapy and the risk of acute myocardial infarction, stroke, and death.

OBJECTIVE: To determine whether nicotine replacement therapy (NRT) is associated with an increased risk of acute myocardial infarction, acute stroke, or death. DESIGN: Self control case series analysis of data from The Health Improvement Network (THIN) to estimate the relative incidence of myocardial infarction and stroke in four 14 day periods before and after the first prescription for NRT. SETTING: THIN is a computerised general practice database. SUBJECTS: Patients contributing data to THIN. INTERVENTIONS: Observational study of NRT. MAIN OUTCOMES: Acute myocardial infarction, acute stroke, and death. RESULTS: 33,247 individuals had been prescribed NRT, of whom 861 had had a myocardial infarction and 506 a stroke. There was a progressive increase in the incidence of first myocardial infarction in the 56 days leading up to the first NRT prescription (overall incidence ratio 5.55, 95% confidence interval (CI) 4.42 to 6.98), but the incidence fell after this time and was not increased in the 56 days after starting NRT (incidence ratio 1.27, 95% CI 0.82 to 1.97). The results were similar for second myocardial infarction and stroke, and for subgroups of people with pre-existing angina and hypertension. There were 960 deaths in our cohort during a mean follow up period of 2.6 years after starting NRT, with no evidence of an increased mortality in the 56 days after the NRT prescription (incidence ratio 0.86, 95% CI 0.60 to 1.23). CONCLUSIONS: The use of NRT is not associated with any increase in the risk of myocardial infarction, stroke, or death.

Adult↗
PubMed2005

Respiratory symptoms in older people and their association with mortality.

BACKGROUND: A study was undertaken to assess the prevalence of reported respiratory symptoms in a population aged over 75 years and their association with mortality. METHODS: A total of 14 458 people aged 75 years and over participating in a trial of health screening of older people in general practice answered questions on three respiratory symptoms: cough, sputum production, and wheeze. The association of symptoms with mortality was examined for all cause and respiratory causes of death taking account of potential confounders. RESULTS: Coughing up phlegm in winter mornings had a prevalence of 27.0% (95% confidence interval (CI) 26.8 to 27.2). Those with this symptom had an adjusted hazard ratio for all cause mortality of 1.35 (95% CI 1.21 to 1.50), p<0.001 and for respiratory specific mortality of 2.01 (95% CI 1.66 to 2.41), p<0.001. Phlegm at any time of the day in winter had a prevalence of 16.5% (95% CI 16.3 to 16.7) with hazard ratios for all cause and respiratory specific mortality of 1.28 (95% CI 1.15 to 1.42) and 2.28 (95% CI 1.92 to 2.70), p<0.001. Wheeze or whistling from the chest had a prevalence of 14.3% (95% CI 14.1 to 14.5) with hazard ratios of 1.45 (95% CI 1.31 to 1.61) and 2.86 (95% CI 2.45 to 3.35), p<0.001. CONCLUSIONS: The prevalence of respiratory symptoms is widespread among elderly people and their presence is a strong predictor of mortality.

Aged↗
PubMed2003

Cataract and the use of statins: a case-control study.

BACKGROUND: In animal studies, statins have induced cataract formation. Because incident cataract is relatively uncommon, studies in humans have been unable to exclude a clinically important effect. AIMS: To assess the risk of cataract associated with the use of statins, and whether it is increased by concurrent use of drugs that inhibit the cytochrome P450 system. DESIGN: Population-based case-control study. METHODS: Patients were randomly sampled from the UK General Practice Research Database. The study included 15,479 people with cataract and 15,479 controls matched for age, sex, practice and observation period. RESULTS: The crude odds ratio (OR) for the association between any recorded exposure to statins and cataract was 1.41 (95%CI 1.21-1.65), but this reduced to 1.04 (95%CI 0.89-1.23, p=0.6) after adjustment for consultation rate. There was no evidence that the risk increased with higher doses or longer duration of statin use, or that the risk varied by individual statin. There was no evidence that the risk of cataract was increased by concurrent use of statins and drugs that inhibit the cytochrome P450 system. DISCUSSION: In the short- and medium-term, statins do not seem to be associated with an increased risk of cataract. The need to assess the effects of long-term statin exposure on the eye remains.

Aged↗
PubMed2003

A population based case-control study of cataract and inhaled corticosteroids.

BACKGROUND/AIMS: Exposure to systemic corticosteroid use is known to be associated with a risk of cataract. Whether low doses of inhaled corticosteroids are associated with an increased risk of cataract is not known. This study was undertaken to quantify the risk of cataract associated with the use of inhaled corticosteroids and assess whether there is a dose-response relation. METHODS: A population based case-control study based on the General Practice Research Database in the United Kingdom. 15 479 people with cataract and 15 479 controls were matched for age, sex, practice, and observation period. RESULTS: The crude odds ratio for the association between any recorded exposure to inhaled corticosteroids and cataract was 1.58 (95% CI 1.46 to 1.71), reduced to 1.10 (95% CI 1.00 to 1.20) after adjustment for systemic corticosteroid exposure and consultation rate. There was a dose-response relation, the adjusted odds ratio rising from 0.99 (95% CI 0.87 to 1.13) at daily doses up to 400 micro g to 1.69 (95% CI 1.17 to 2.43) for daily doses greater than 1600 micro g. The association was also stronger with increasing duration of use. CONCLUSION: Higher doses and longer duration of exposure to inhaled corticosteroids are associated with an increased risk of cataract. The lowest doses compatible with good control of airways disease should be used. The risk of cataract associated with high doses of inhaled corticosteroids needs to be more widely appreciated.

Administration, Inhalation↗
PubMed2002

Prevalence of visual impairment in people aged 75 years and older in Britain: results from the MRC trial of assessment and management of older people in the community.

AIMS: To measure the prevalence of visual impairment in a large representative sample of people aged 75 years and over participating in the MRC trial of assessment and management of older people in the community. METHODS: 53 practices in the MRC general practice research framework. Data were obtained from 14 600 participants aged 75 years and older. Prevalence of visual impairment overall (binocular visual acuity <6/18) which was categorised separately into low vision (binocular visual acuity <6/18-3/60) or blindness (binocular visual acuity of <3/60). The prevalence of binocular acuity <6/12 was presented for comparison with other studies. Visual acuity was measured using Glasgow acuity charts; glasses, if worn, were not removed. RESULTS: Visual acuity was available for 14 600 people out of 21 241 invited (69%). Among people with visual acuity data, 12.4% overall (1803) were visually impaired (95% confidence intervals 10.8% to 13.9%); 1501 (10.3%) were categorised as having low vision (8.7% to 11.8%), and 302 (2.1%) were blind (1.8% to 2.4%). At ages 75-79, 6.2% of the cohort were visually impaired (5.1% to 7.3%) with 36.9% at age 90+ (32.5% to 41.3%). At ages 75-79, 0.6% (0.4% to 0.8%) of the study population were blind, with 6.9% (4.8% to 9.0%) at age 90+. In multivariate regression, controlling for age, women had significant excess risk of visual impairment (odds ratio 1.43, 95% confidence interval 1.29 to 1.58). Overall, 19.9% of study participants had a binocular acuity of less than 6/12 (17.8% to 22.0%). CONCLUSION: The results from this large study show that visual impairment is common in the older population and that this risk increases rapidly with advancing age, especially for women. A relatively conservative measure of visual impairment was used. If visual impairment had been defined as visual acuity of <6/12 (American definition of visual impairment), the age specific prevalence estimates would have increased by 60%.

Age Factors↗
PubMed2001

Randomised comparison of three methods of administering a screening questionnaire to elderly people: findings from the MRC trial of the assessment and management of older people in the community.

OBJECTIVE: To compare three different methods of administering a brief screening questionnaire to elderly people: post, interview by lay interviewer, and interview by nurse. DESIGN: Randomised comparison of methods within a cluster randomised trial. SETTING: 106 general practices in the United Kingdom. PARTICIPANTS: 32 990 people aged 75 years or over registered with participating practices. MAIN OUTCOME MEASURES: Response rates, proportion of missing values, prevalence of self reported morbidity, and sensitivity and specificity of self reported measures by method of administration of questionnaire for four domains. RESULTS: The response rate was higher for the postal questionnaire than for the two interview methods combined (83.5% v 74.9%; difference 8.5%, 95% confidence interval 4.4% to 12.7%, P<0.001). The proportion of missing or invalid responses was low overall (mean 2.1%) but was greater for the postal method than for the interview methods combined (4.1% v 0.9%; difference 3.2%, 2.7% to 3.6%, P<0.001). With a few exceptions, levels of self reported morbidity were lower in the interview groups, particularly for interviews by nurses. The sensitivity of the self reported measures was lower in the nurse interview group for three out of four domains, but 95% confidence intervals for the estimates overlapped. Specificity of the self reported measures varied little by method of administration. CONCLUSIONS: Postal questionnaires were associated with higher response rates but also higher proportions of missing values than were interview methods. Lower estimates of self reported morbidity were obtained with the nurse interview method and to a lesser extent with the lay interview method than with postal questionnaires.

Aged↗
PubMed2001

A case-control study of autism and mumps-measles-rubella vaccination using the general practice research database: design and methodology.

BACKGROUND: An association between mumps-measles-rubella (MMR) vaccination and the onset of symptoms typical of autism has recently been suggested. This has led to considerable concern about the safety of the vaccine. METHODS: A matched case-control study using data derived form the United Kingdom General Practice Research Database. Children with a possible diagnosis of autism will be identified from their electronic health records. All diagnoses will be validated by a detailed review of hospital letters and by using information derived from a parental questionnaire. Ten controls per case will be selected from the database. Conditional logistic regression will be used to assess the association between MMR vaccination and autism. In addition case series analyses will be undertaken to estimate the relative incidence of onset of autism in defined time intervals after vaccination. The study is funded by the United Kingdom Medical Research Council. DISCUSSION: Electronic health databases offer tremendous opportunities for evaluating the adverse effects of vaccines. However there is much scope for bias and confounding. The rigorous validation of all diagnoses and the collection of additional information by parental questionnaire in this study are essential to minimise the possibility of misleading results.

Age of Onset↗