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Andrew J Hall - One of the best experts on this subject based on the ideXlab platform.
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validation and validity of diagnoses in the general practice Research Database a systematic review
British Journal of Clinical Pharmacology, 2010Co-Authors: Emily Herrett, Marieke W Schoonen, Sara L Thomas, Liam Smeeth, Andrew J HallAbstract:AIMS To investigate the range of methods used to validate diagnoses in the General Practice Research Database (GPRD), to summarize findings and to assess the quality of these validations. METHODS A systematic literature review was performed by searching PubMed and Embase for publications using GPRD data published between 1987 and April 2008. Additional publications were identified from conference proceedings, back issues of relevant journals, bibliographies of retrieved publications and relevant websites. Publications that reported attempts to validate disease diagnoses recorded in the GPRD were included. RESULTS We identified 212 publications, often validating more than one diagnosis. In total, 357 validations investigating 183 different diagnoses met our inclusion criteria. Of these, 303 (85%) utilized data from outside the GPRD to validate diagnoses. The remainder utilized only data recorded in the Database. The median proportion of cases with a confirmed diagnosis was 89% (range 24-100%). Details of validation methods and results were often incomplete. CONCLUSIONS A number of methods have been used to assess validity. Overall, estimates of validity were high. However, the quality of reporting of the validations was often inadequate to permit a clear interpretation. Not all methods provided a quantitative estimate of validity and most methods considered only the positive predictive value of a set of diagnostic codes in a highly selected group of cases. We make recommendations for methodology and reporting to strengthen further the use of the GPRD in Research.
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how accurate are diagnoses for rheumatoid arthritis and juvenile idiopathic arthritis in the general practice Research Database
Arthritis & Rheumatism, 2008Co-Authors: Sara L Thomas, C. Cooper, Liam Smeeth, Christopher J Edwards, Andrew J HallAbstract:Objective. To identify characteristics that predict a valid rheumatoid arthritis (RA) or juvenile idiopathic arthritis (JIA) diagnosis among RA- and JIA-coded individuals in the General Practice Research Database (GPRD), and to assess limitations of this type of diagnostic validation. Methods. Four RA and 2 JIA diagnostic groups were created with differing strengths of evidence of RA/JIA (Group 1 = strongest evidence), based oil RA/JIA medical codes. Individuals were sampled from each group and clinical and 0 prescription data were extracted from anonymized hospital/practice correspondence and electronic records. American College of Rheumatology and International League of Associations for Rheumatology diagnostic criteria were, used to validate diagnoses. A data- derived diagnostic algorithm that maximized sensitivity and specificity was identified using logistic regression. Results. Among 223 RA-coded individuals. the diagnostic algorithm classified individuals as having RA if they had an appropriate GPRD disease-modifying antirheumatic drug prescription or 3 other GPRD characteristics: >1 RA code during followup, RA diagnostic Group 1 or 2, and no later alternative diagnostic code. This algorithm had >80% sensitivity and specificity when applied to a test data set. Among 101 JIA-coded individuals, the strongest predictor of a valid diagnosis was a Group 1 diagnostic code (>90% sensitivity and specificity). Conclusion. Validity of an RA diagnosis among RA-coded GPRD individuals appears high for patients with specific characteristics. The findings are important for both interpreting results Of Published GPRD studies and identifying RA/JIA patients for future GPRD-based Research. However, several limitations were identified, and further debate is needed on how best to validate chronic disease diagnoses in the GPRD
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a cohort study of the effectiveness of influenza vaccine in older people performed using the united kingdom general practice Research Database
The Journal of Infectious Diseases, 2004Co-Authors: Punam Mangtani, Phillippa M Cumberland, Cathy R Hodgson, J A Roberts, Felicity T Cutts, Andrew J HallAbstract:Background. The effectiveness of influenza vaccination against hospitalization and death can only ethically be assessed in observational studies. A concern is that individuals who are vaccinated are healthier than individuals who are not vaccinated, potentially biasing estimates of effectiveness upward. Methods. We conducted a historical cohort study of individuals 164 years of age, for whom there were data available in the General Practice Research Database for 1989 to 1999 in England and Wales. Rates of admissions for acute respiratory diseases and rates of death due to respiratory disease were compared over 692,819 personyears in vaccine recipients and 1,534,280 person-years in vaccine nonrecipients. Results. The pooled effectiveness of vaccine against hospitalizations for acute respiratory disease was 21% (95% confidence interval [CI], 17%‐26%). The rate reduction attributable to vaccination was 4.15 hospitalizations/100,000 person-weeks in the influenza season. Among vaccine recipients, no important reduction in the number of admissions to the hospital was seen outside influenza seasons. The pooled effectiveness of vaccine against deaths due to respiratory disease was 12% (95% CI, 8%‐16%). A greater proportionate reduction was seen among people without medical disorders, but absolute rate reduction was higher in individuals with medical disorders, compared with individuals without such disorders (6.14 deaths due to respiratory disease/100,000 person-weeks vs. 3.12 deaths due to respiratory disease/100,000 person-weeks). Clear protection against death due to all causes was not seen. Conclusions. Influenza vaccination reduces the number of hospitalizations and deaths due to respiratory disease, after correction for confounding in individuals 164 years of age who had a high risk or a low risk for influenza. For elderly people, untargeted influenza vaccination is of confirmed benefit against serious outcomes.
Ian C K Wong - One of the best experts on this subject based on the ideXlab platform.
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effect of antibiotics for otitis media on mastoiditis in children a retrospective cohort study using the united kingdom general practice Research Database
Pediatrics, 2009Co-Authors: Paula L Thompson, Ruth Gilbert, Paul F Long, Sonia Saxena, Mike Sharland, Ian C K WongAbstract:BACKGROUND: Information is needed on whether mastoiditis has increased in association with the decline in antibiotics prescribed to children by primary care physicians in the United Kingdom. OBJECTIVE: To determine time trends in mastoiditis incidence, the frequency of antecedent otitis media, and the effect of antibiotics for otitis media on the risk of mastoiditis in children. PATIENTS AND METHODS: We conducted a retrospective cohort study by using the UK General Practice Research Database. Children aged 3 months to 15 years between 1990 and 2006 were included. Risk of mastoiditis within 3 months after otitis media diagnosis and the protective effect of antibiotics were determined. RESULTS: There were 2 622 348 children within the General Practice Research Database; 854 had mastoiditis, only one third of whom (35.7%) had antecedent otitis media. Mastoiditis incidence remained stable between 1990 and 2006 ( approximately 1.2 per 10 000 child-years). Risk of mastoiditis, after otitis media, was 1.8 per 10 000 episodes (139 of 792 623) after antibiotics compared with 3.8 per 10 000 (149 of 389 649) without antibiotics, and increased with age. Antibiotics halved the risk of mastoiditis. General practitioners would need to treat 4831 otitis media episodes with antibiotics to prevent 1 child from developing mastoiditis. If antibiotics were no longer prescribed for otitis media, an extra 255 cases of childhood mastoiditis would occur, but there would be 738 775 fewer antibiotic prescriptions per year in the United Kingdom. CONCLUSIONS: Most children with mastoiditis have not seen their general practitioner for otitis media. Antibiotics halve the risk of mastoiditis, but the high number of episodes needing treatment to prevent 1 case precludes the treatment of otitis media as a strategy for preventing mastoiditis. Although mastoiditis is a serious disease, most children make an uncomplicated recovery after mastoidectomy or intravenous antibiotics. Treating these additional otitis media episodes could pose a larger public health problem in terms of antibiotic resistance.
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effect of antibiotics for otitis media on mastoiditis in children a retrospective cohort study using the united kingdom general practice Research Database
Pediatrics, 2009Co-Authors: Paula L Thompson, Ruth Gilbert, Paul F Long, Sonia Saxena, Mike Sharland, Ian C K WongAbstract:BACKGROUND. Information is needed on whether mastoiditis has increased in association with the decline in antibiotics prescribed to children by primary care physicians in the United Kingdom. OBJECTIVE. To determine time trends in mastoiditis incidence, the frequency of antecedent otitis media, and the effect of antibiotics for otitis media on the risk of mastoiditis in children. PATIENTS AND METHODS. We conducted a retrospective cohort study by using the UK General Practice Research Database. Children aged 3 months to 15 years between 1990 and 2006 were included. Risk of mastoiditis within 3 months after otitis media diagnosis and the protective effect of antibiotics were determined. RESULTS. There were 2 622 348 children within the General Practice Research Database; 854 had mastoiditis, only one third of whom (35.7%) had antecedent otitis media. Mastoiditis incidence remained stable between 1990 and 2006 (∼1.2 per 10 000 child-years). Risk of mastoiditis, after otitis media, was 1.8 per 10 000 episodes (139 of 792 623) after antibiotics compared with 3.8 per 10 000 (149 of 389 649) without antibiotics, and increased with age. Antibiotics halved the risk of mastoiditis. General practitioners would need to treat 4831 otitis media episodes with antibiotics to prevent 1 child from developing mastoiditis. If antibiotics were no longer prescribed for otitis media, an extra 255 cases of childhood mastoiditis would occur, but there would be 738 775 fewer antibiotic prescriptions per year in the United Kingdom. CONCLUSIONS. Most children with mastoiditis have not seen their general practitioner for otitis media. Antibiotics halve the risk of mastoiditis, but the high number of episodes needing treatment to prevent 1 case precludes the treatment of otitis media as a strategy for preventing mastoiditis. Although mastoiditis is a serious disease, most children make an uncomplicated recovery after mastoidectomy or intravenous antibiotics. Treating these additional otitis media episodes could pose a larger public health problem in terms of antibiotic resistance.
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a drug utilisation study of antidepressants in children and adolescents using the general practice Research Database
Archives of Disease in Childhood, 2004Co-Authors: Macey L Murray, C S De Vries, Ian C K WongAbstract:Aims: To characterise prescribing patterns of antidepressants (ATDs) to children and adolescents aged ⩽18 years in the UK. Methods: Subjects issued at least one ATD prescription between 1 January 1992 and 31 December 2001 were identified from the UK General Practice Research Database. Prescribing patterns, annual prevalence, morbidity patterns, and time to discontinuation of ATD use were identified. Results: A total of 24 976 subjects received 93 091 prescriptions; 51 868 (55.7%), 38 429 (41.3%), and 2708 (2.9%) prescriptions were for tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), and other ATDs respectively. ATD prevalence increased 1.7-fold from 1992 to 2001. TCA prevalence decreased by 30% from 3.6 to 2.5 per 1,000; SSRI prevalence increased 10 times from 0.5 to 4.6 per 1,000. In new ATD users aged ⩽10 years, the most common diagnosis associated with TCA use was nocturnal enuresis (75.1%); in those aged ⩾15 years, it was depression (45.8%). Depression was also associated with SSRI use (69.0%). For new users with depression, the median treatment durations for TCAs and SSRIs were 30 and 58 days respectively. TCA users were more likely to terminate treatment than SSRI users (TCAs v fluoxetine: 1.40, 95% CI 1.32 to 1.47; non-fluoxetine SSRIs v fluoxetine: 1.01, 95% CI 0.96 to 1.07). Conclusions: SSRIs have gained popularity for the treatment of depression compared with TCAs. TCAs are still used despite their lack of efficacy in prepubertal depression and their moderate effect in adolescents. However, >50% of subjects discontinue treatment after two months, with TCA users stopping earlier than SSRI users.
C. Cooper - One of the best experts on this subject based on the ideXlab platform.
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Fracture rate in patients with myasthenia gravis: the general practice Research Database
Osteoporosis International, 2013Co-Authors: S. Pouwels, A. Boer, M. K. Javaid, D. Hilton-jones, J. Verschuuren, C. Cooper, H. G. Leufkens, F. VriesAbstract:The aim of this study was to evaluate fracture risk after onset of myasthenia gravis using the UK General Practice Research Database. Overall fracture risk is not statistically increased compared with age- and gender-matched controls irrespective of glucocorticoid use, but was increased in those using antidepressants, anxiolytics or anticonvulsants. Introduction Myasthenia gravis (MG) is a neuromuscular disease which has been associated with an increased falls risk and glucocorticoid-induced osteoporosis, recognized determinants of increased fracture risk. The aim of this study was to evaluate the risk of fracture after onset of MG. Methods We conducted a retrospective cohort study using the UK General Practice Research Database (1987–2009). Each MG patient was matched by age, sex, calendar time and practice to up to six patients without a history of MG and we identified all fractures and those associated with osteoporosis. Results Compared to the control cohort, there was no statistically significant increased risk observed in patients with MG for any fracture (adjusted hazard ratio [AHR] 1.11; 95 % confidence interval [CI], 0.84–1.47) or osteoporotic fractures (AHR 0.98 [95 % CI 0.67–1.41]). Further, use of oral glucocorticoids up to a cumulative dose exceeding 5 g prednisolone equivalents did not increase risk of osteoporotic fracture (AHR 0.99 [95 % CI, 0.31–3.14]) compared with MG patients without glucocorticoid exposure. However, fracture risk was higher in patients with MG prescribed antidepressants (AHR 3.27 [95 % CI, 1.63–6.55]), anxiolytics (AHR 2.18 [95 % CI, 1.04–4.57]) and anticonvulsants (AHR 6.88 [95 % CI, 2.91–16.27]). Conclusion Overall risk of fracture in patients with MG is not statistically increased compared with age- and gender-matched controls irrespective of glucocorticoid use but was increased in those using antidepressants, anxiolytics or anticonvulsants. These findings have implications in strategies preserving bone health in patients with MG.
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how accurate are diagnoses for rheumatoid arthritis and juvenile idiopathic arthritis in the general practice Research Database
Arthritis & Rheumatism, 2008Co-Authors: Sara L Thomas, C. Cooper, Liam Smeeth, Christopher J Edwards, Andrew J HallAbstract:Objective. To identify characteristics that predict a valid rheumatoid arthritis (RA) or juvenile idiopathic arthritis (JIA) diagnosis among RA- and JIA-coded individuals in the General Practice Research Database (GPRD), and to assess limitations of this type of diagnostic validation. Methods. Four RA and 2 JIA diagnostic groups were created with differing strengths of evidence of RA/JIA (Group 1 = strongest evidence), based oil RA/JIA medical codes. Individuals were sampled from each group and clinical and 0 prescription data were extracted from anonymized hospital/practice correspondence and electronic records. American College of Rheumatology and International League of Associations for Rheumatology diagnostic criteria were, used to validate diagnoses. A data- derived diagnostic algorithm that maximized sensitivity and specificity was identified using logistic regression. Results. Among 223 RA-coded individuals. the diagnostic algorithm classified individuals as having RA if they had an appropriate GPRD disease-modifying antirheumatic drug prescription or 3 other GPRD characteristics: >1 RA code during followup, RA diagnostic Group 1 or 2, and no later alternative diagnostic code. This algorithm had >80% sensitivity and specificity when applied to a test data set. Among 101 JIA-coded individuals, the strongest predictor of a valid diagnosis was a Group 1 diagnostic code (>90% sensitivity and specificity). Conclusion. Validity of an RA diagnosis among RA-coded GPRD individuals appears high for patients with specific characteristics. The findings are important for both interpreting results Of Published GPRD studies and identifying RA/JIA patients for future GPRD-based Research. However, several limitations were identified, and further debate is needed on how best to validate chronic disease diagnoses in the GPRD
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the changing use of disease modifying anti rheumatic drugs in individuals with rheumatoid arthritis from the united kingdom general practice Research Database
Rheumatology, 2005Co-Authors: Christopher J Edwards, N K Arden, D Fisher, J C Saperia, I Reading, T P Van Staa, C. CooperAbstract:Objectives. To describe the use of disease-modifying anti-rheumatic drugs (DMARDs) in the treatment of rheumatoid arthritis (RA) and changing trends in their use. Methods. We used the General Practice Research Database (GPRD) to describe DMARD use by patients with RA identified using ICD-9 codes. The GPRD is a UK national Database containing records of more than 7 million individuals from 683 general practices. Subjects were studied between 1987 and 2002. The prevalence and duration of individual DMARD use and changing trends in DMARD use were investigated. Results. Thirty-four thousand three hundred and sixty-four patients with RA were identified. Only 17 115 (50%) individuals were prescribed at least one DMARD during the study period. The most commonly prescribed DMARD over the study period was sulphasalazine (46.3%) and then methotrexate (31.4%). Use of methotrexate has increased 17-fold (1.8% of all DMARD prescriptions in 1988 to 30% in 2002) whereas use of gold has fallen (13.2% to 2.3%). Analysis of DMARD persistence using Kaplan–Meier survival curves showed the methotrexate use persisted significantly longer than other DMARDs with an estimated median of 8.1 yr. Prednisolone was used in up to 50% of RA patients in any one year and has remained fairly constant throughout the study period. Conclusions. Large numbers of individuals with a clinical diagnosis of RA identified from a large primary care Database are not receiving DMARDs. This work suggests that many individuals with RA have not been treated appropriately and this may have major long-term consequences on joint damage and general health.
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epidemiology of childhood fractures in britain a study using the general practice Research Database
Journal of Bone and Mineral Research, 2004Co-Authors: C. Cooper, Elaine M Dennison, Herbert G M Leufkens, Nick Bishop, Tjeerd P Van StaaAbstract:UNLABELLED: A population-based British cohort study, including approximately 6% of the population, was used to derive age- and sex-specific incidence rates of fractures during childhood. Fractures were more common among boys than girls, with peak incidences at 14 and 11 years of age, respectively. At childhood peak, incidence rates were only surpassed later in life at 85 years of age among women and never among men. INTRODUCTION: Fractures account for 25% of accidents and injuries in childhood; however, the descriptive epidemiology of childhood fractures remains uncertain. MATERIALS AND METHODS: Age- and sex-specific incidence rates for fractures at various skeletal sites were derived from the General Practice Research Database (a population-based British cohort containing computerized medical records of approximately 7,000,000 residents) between 1988 and 1998. RESULTS: A total of 52,624 boys and 31,505 girls sustained one or more fractures over the follow-up period, for a rate of 133.1/10,000 person-years. Fractures were more common in boys (161.6/10,000 person-years) than girls (102.9/10,000 person-years). The most common fracture in both sexes was that of the radius/ulna (30%). Fracture incidence was greater among boys than girls at all ages, with the peak incidence at 14 years of age among boys and 11 years of age among girls. Marked geographic variation was observed in standardized fracture incidence, with significantly (p < 0.01) higher rates observed in Northern Ireland, Wales, and Scotland compared with southeast England. CONCLUSIONS: Fractures are a common problem in childhood, with around one-third of boys and girls sustaining at least one fracture before 17 years of age. Rates are higher among boys than girls, and male incidence rates peak later than those among females. At their childhood peak, the incidence of fractures (boys, 3%; girls, 1.5%) is only surpassed at 85 years of age among women and never among men. The most common site affected in both genders is the radius/ulna. Studies to clarify the pathogenesis of these fractures, emphasizing bone fragility, are now required.
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epidemiology of childhood fractures in britain a study using the general practice Research Database
Journal of Bone and Mineral Research, 2004Co-Authors: C. Cooper, Elaine M Dennison, Herbert G M Leufkens, Nick Bishop, Tjeerd P Van StaaAbstract:A population-based British cohort study, including 6% of the population, was used to derive age- and sex-specific incidence rates of fractures during childhood. Fractures were more common among boys than girls, with peak incidences at 14 and 11 years of age, respectively. At childhood peak, incidence rates were only surpassed later in life at 85 years of age among women and never among men. Introduction: Fractures account for 25% of accidents and injuries in childhood; however, the descriptive epidemiology of childhood fractures remains uncertain. Materials and Methods: Age- and sex-specific incidence rates for fractures at various skeletal sites were derived from the General Practice Research Database (a population-based British cohort containing computerized medical records of 7,000,000 residents) between 1988 and 1998. Results: A total of 52,624 boys and 31,505 girls sustained one or more fractures over the follow-up period, for a rate of 133.1/10,000 person-years. Fractures were more common in boys (161.6/10,000 person-years) than girls (102.9/10,000 person-years). The most common fracture in both sexes was that of the radius/ulna (30%). Fracture incidence was greater among boys than girls at all ages, with the peak incidence at 14 years of age among boys and 11 years of age among girls. Marked geographic variation was observed in standardized fracture incidence, with significantly (p Conclusions: Fractures are a common problem in childhood, with around one-third of boys and girls sustaining at least one fracture before 17 years of age. Rates are higher among boys than girls, and male incidence rates peak later than those among females. At their childhood peak, the incidence of fractures (boys, 3%; girls, 1.5%) is only surpassed at 85 years of age among women and never among men. The most common site affected in both genders is the radius/ulna. Studies to clarify the pathogenesis of these fractures, emphasizing bone fragility, are now required.
Richard Hubbard - One of the best experts on this subject based on the ideXlab platform.
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early exposure to infections and antibiotics and the incidence of allergic disease a birth cohort study with the west midlands general practice Research Database
The Journal of Allergy and Clinical Immunology, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, J Collins, H Heatlie, Martin Frischer, Christopher Smith, Richard HubbardAbstract:Abstract Background: It has been suggested that the rise in prevalence of allergic disease in westernized countries is due in part to a decrease in exposure to infections and an increase in the use of antibiotics early in life. Objective: The purpose of this investigation was to quantify the relationships between (1) exposure to personal infections, infections in siblings, and use of antibiotics in early life and (2) the incidence of allergic disease. Methods: Using the West Midlands section of the UK General Practice Research Database, we established a historical birth cohort of children (N = 29,238). For each child, we identified all personal infections and infections in siblings and determined the use of antibiotics in early life; we also noted incident diagnoses of asthma, eczema, and hay fever. The data were analyzed through use of Cox regression. Results: There was no clear protective effect of exposure to either personal infections or infections in siblings with respect to the incidence of allergic disease. Antibiotic exposure was associated with an increased risk of developing allergic disease in a dose-related manner: having 4 or more courses of antibiotics in the first year of life was associated with an increased incidence of asthma (hazard ratio [HR], 3.13; 95% CI, 2.75-3.57), eczema (HR, 1.48; 95% CI, 1.31-1.68), and hay fever (HR, 2.12; 95% CI, 1.68-2.66). However, adjusting for consulting behavior reduced these effects (adjusted HR [95% CI]: asthma, 1.99 [1.72-2.31]; eczema, 1.01 [0.88-1.17]; hay fever, 1.14 [0.88-1.47]). Conclusions: We found no evidence that exposure to infections reduced the incidence of allergic disease, and infections did not explain the previous findings of a strong birth order effect in this cohort. The use of antibiotics might be associated with early diagnoses of allergic disease. (J Allergy Clin Immunol 2002;109:43-50.)
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siblings multiple births and the incidence of allergic disease a birth cohort study using the west midlands general practice Research Database
Thorax, 2001Co-Authors: Tricia M Mckeever, Sarah Lewis, C J P Smith, J Collins, H Heatlie, Martin Frischer, Richard HubbardAbstract:Background—The presence of older siblings reduces the risk of developing hay fever, eczema and atopy, but findings for asthma have been inconsistent. Whether twins have a reduced risk of allergic disease is also unclear. We have investigated these questions in a birth cohort analysis of the West Midlands General Practice Research Database (GPRD). Methods—Our birth cohort included 29 238 children. The incidence of allergic disease was examined according to the number of siblings, multiple births, and parental allergic disease and smoking habit using Cox regression. Results—There was a dose related decrease in the incidence of eczema and hay fever with increasing number of older siblings (hazard ratio for children with three or more older siblings compared with none 0.70 (95% CI 0.64 to 0.76) for eczema and 0.67 (95% CI 0.52 to 0.86) for hay fever). In contrast, the presence of older siblings increased the incidence of asthma (HR 1.17, 95% CI 1.06 to 1.29), although this eVect was strongly dependent on age of diagnosis. For children diagnosed over the age of 2 years the presence of older siblings was protective (HR 0.66, 95% CI 0.52 to 0.82), while below this age the reverse was true (HR 1.38, 95% CI 1.24 to 1.54). Members of a multiple birth had a reduced incidence of all three allergic diseases. Birth order and multiple birth eVects were independent of sex, maternal age, consulting behaviour, and parental allergy and smoking habit. Conclusions—The presence of older siblings and being a member of a multiple birth appears to protect against the development of eczema, hay fever, and asthma diagnosed after the age of 2. In contrast, the presence of older siblings increases the incidence of early asthma. (Thorax 2001;56:758‐762)
Tjeerd Van Staa - One of the best experts on this subject based on the ideXlab platform.
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cancer recording and mortality in the general practice Research Database and linked cancer registries
Pharmacoepidemiology and Drug Safety, 2013Co-Authors: Rachael Boggon, Tjeerd Van Staa, Michael Chapman, Arlene M Gallagher, Tarek A Hammad, Mike A RichardsAbstract:Purpose Large electronic datasets are increasingly being used to evaluate healthcare delivery. The aim of this study was to compare information held by cancer registries with that of the General Practice Research Database (GPRD). Methods A convenience sample of 101 020 patients aged 40+ years drawn from GPRD formed the primary data source. This cohort was derived from a larger sample originally established for a cohort study of diabetes. GPRD records were linked with those from cancer registries in the National Cancer Data Repository (NCDR). Concordance between the two datasets was then evaluated. For cases recorded only on one dataset, validation was sought from other datasets (Hospital Episode Statistics and death registration) and by detailed analysis of a subset of GPRD records. Results A total of 5797 cancers (excluding non-melanomatous skin cancer) were recorded on GPRD. Of these cases, 4830 were also recorded on NCDR (concordance rate of 83.3%). Of the 976 cases recorded on GPRD but not on NCDR, 528 were present also in the hospital records or death certificates. Of the 341 cases recorded on NCDR but not on GPRD, 307 were recorded in these other two datasets. Rates of concordance varied by cancer type. Cancer registries recorded larger numbers of patients with lung, colorectal, and pancreatic cancers, whereas GPRD recorded more haematological cancers and melanomas. As expected, GPRD recorded significantly more non-melanomatous skin cancer. Concordance decreased with increasing age. Conclusion Although concordance levels were reasonably high, the findings from this study can be used to direct efforts for better recording in both datasets. Copyright © 2012 Crown copyright.
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recent advances in the utility and use of the general practice Research Database as an example of a uk primary care data resource
Therapeutic advances in drug safety, 2012Co-Authors: Tim Williams, Tjeerd Van Staa, Shivani Puri, Susan EatonAbstract:Since its inception in the mid-1980s, the General Practice Research Database (GPRD) has undergone many changes but remains the largest validated and most utilised primary care Database in the UK. Its use in pharmacoepidemiology stretches back many years with now over 800 original Research papers. Administered by the Medicines and Healthcare products Regulatory Agency since 2001, the last 5 years have seen a rebuild of the Database processing system enhancing access to the data, and a concomitant push towards broadening the applications of the Database. New methodologies including real-world harm–benefit assessment, pharmacogenetic studies and pragmatic randomised controlled trials within the Database are being implemented. A substantive and unique linkage program (using a trusted third party) has enabled access to secondary care data and disease-specific registry data as well as socio-economic data and death registration data. The utility of anonymised free text accessed in a safe and appropriate manner is being explored using simple and more complex techniques such as natural language processing.
