Backdating of events in electronic primary health care data: should one censor at the date of last data collection

PURPOSE: Studies using primary care databases often censor follow-up at the date data are last collected from clinical computer systems (last collection date (LCD)). We explored whether this results in the selective exclusion of events entered in the electronic health records after their date of occurrence, that is, backdated events. METHODS: We used data from The Health Improvement Network (THIN). Using two versions of the database, we identified events that were entered into a later (THIN14) but not an earlier version of the database (THIN13) and investigated how the number of entries changed as a function of time since LCD. Times between events and the dates they were recorded were plotted as a function of time since the LCD in an effort to determine appropriate points at which to censor follow-up. RESULTS: There were 356 million eligible events in THIN14 and 355 million eligible events in THIN13. When comparing the two data sets, the proportion of missing events in THIN13 was highest in the month prior to the LCD (9.6%), decreasing to 5.2% at 6 months and 3.4% at 12 months. The proportion of missing events was largest for events typically diagnosed in secondary care such as neoplasms (28% in the month prior to LCD) and negligible for events typically diagnosed in primary care such as respiratory events (2% in the month prior to LCD). CONCLUSIONS: Studies using primary care databases, particularly those investigating events typically diagnosed outside primary care, should censor follow-up prior to the LCD to avoid underestimation of event rates

Recording and treatment of premenstrual syndrome in UK general practice: a retrospective cohort study

OBJECTIVES: To investigate the rate of recording of premenstrual syndrome diagnoses in UK primary care and describe pharmacological treatments initiated following a premenstrual syndrome (PMS) diagnosis. DESIGN: Retrospective cohort study. SETTING: UK primary care. PARTICIPANTS: Women registered with a practice contributing to The Health Improvement Network primary care database between 1995 and 2013. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the rate of first premenstrual syndrome records per 1000 person years, stratified by calendar year and age. The secondary outcome was the proportions of women with a premenstrual syndrome record prescribed a selective serotonin reuptake inhibitor, progestogen, oestrogen, combined oral contraceptive, progestin only contraceptive, gonadotrophin-releasing hormone, danazol and vitamin B6. RESULTS: The rate of recording of premenstrual syndrome diagnoses decreased over calendar time from 8.43 in 1995 to 1.72 in 2013. Of the 38 614 women without treatment in the 6 months prior to diagnosis, 54% received a potentially premenstrual syndrome-related prescription on the day of their first PMS record while 77% received a prescription in the 24 months after. Between 1995 and 1999, the majority of women were prescribed progestogens (23%) or vitamin B6 (20%) on the day of their first PMS record; after 1999, these figures fell to 3% for progestogen and vitamin B6 with the majority of women instead being prescribed a selective serotonin reuptake inhibitor (28%) or combined oral contraceptive (17%). CONCLUSIONS: Recording of premenstrual syndrome diagnoses in UK primary care has declined substantially over time and preferred prescription treatment has changed from progestogen to selective serotonin reuptake inhibitor and combined oral contraceptives

Antiepileptic drugs prescribed in pregnancy and prevalence of major congenital malformations: comparative prevalence studies.

OBJECTIVE: The aim of this study was to examine the prevalence of major congenital malformations associated with antiepileptic drug (AED) treatment in pregnancy. PATIENTS AND METHODS: Using data from The Health Improvement Network, we identified women who have given live birth and their offspring. Four subgroups were selected based on the AED treatment in early pregnancy, valproate, carbamazepine, lamotrigine and women not receiving AED treatment. We compared the prevalence of major congenital malformations within children of these four groups and estimated prevalence ratios (PRs) using Poisson regression adjusted for maternal age, sex of child, quintiles of Townsend deprivation score and indication for treatment. RESULTS: In total, 240,071 women were included in the study. A total of 229 women were prescribed valproate in pregnancy, 357 were prescribed lamotrigine and 334 were prescribed carbamazepine and 239,151 women were not prescribed AEDs. Fifteen out of 229 (6.6%) women prescribed valproate gave birth to a child with a major congenital malformation. The figures for lamotrigine, carbamazepine and women not prescribed AEDs were 2.7%, 3.3% and 2.2%, respectively. The prevalence of major congenital malformation was similar for women prescribed lamotrigine or carbamazepine compared to women with no AED treatment in pregnancy. For women prescribed valproate in polytherapy, the prevalence was fourfold higher. After adjustments, the effect of estimates attenuated, but the prevalence remained two- to threefold higher in women prescribed valproate. CONCLUSION: The results of our study suggest that lamotrigine and carbamazepine are safer treatment options than valproate in pregnancy and should be considered as alternative treatment options for women of childbearing potential and in pregnancy

Initiation and duration of selective serotonin reuptake inhibitor prescribing over time: UK cohort study

BACKGROUND: Recent media reports have focused on the large increase in antidepressants dispensed in England. We investigated this, focusing on selective serotonin reuptake inhibitors (SSRIs). AIMS: To examine the rate of initiation of SSRIs over time and changes over time in the duration of prescribing episodes. METHOD: We estimated initiation and duration of SSRI prescribing from 7 025 802 individuals aged over 18 years and registered with a general practice that contributed data to The Health Improvement Network. RESULTS: Rates of SSRI initiation increased from 1.03 per 100 person-years in 1995 to 2.15 in 2001, but remained stable from then to 2012. The median duration of prescribing episodes increased from 112 to 169 days for episodes starting in 1995 to 2010. CONCLUSIONS: Despite media reports describing an increasing rate of antidepressant prescribing, SSRI initiation rates have stabilised since 2001. However, our results suggest that individuals who take SSRIs are receiving treatment for longer

Surveillance of antenatal influenza vaccination: validity of current systems and recommendations for improvement

Abstract Background: Although influenza vaccination is recommended during pregnancy as standard of care, limited surveillance data are available for monitoring uptake. Our aim was to evaluate the validity of existing surveillance in Western Australia for measuring antenatal influenza immunisations. Methods: The self-reported vaccination status of 563 women who delivered between April and October 2013 was compared against three passive data collection sources: a state-wide antenatal influenza vaccination database maintained by the Department of Health, a public maternity hospital database, and a private health service database. Sensitivity, specificity, and positive and negative predictive values were calculated for each system using self-report as the “gold standard.” Results: The state-wide antenatal vaccination database detected 45.7 % (95 % CI: 40.1–51.4 %) of influenza vaccinations, the public maternity hospital database detected 66.7 % (95 % CI: 55.1–76.9 %), and the private health service database detected 29.1 % (95 % CI: 20.5–39.4 %). Specificity exceeded 90 % and positive predictive values exceeded 80 % for each system. Sensitivity was lowest for women whose antenatal care was provided by a private obstetrician. Conclusions: Existing resources for surveillance of antenatal influenza vaccinations detect 29–67 % of vaccinations. Considering the importance of influenza immunisation as a public health intervention, particularly in pregnant women, improvements to routine monitoring of influenza vaccination is warranted

Does corporate reputation matter? Role of social media in consumer intention to purchase innovative food product

The exponential growth of the corporate reputation in food industry has resulted in innovations in every link of its supply chain. There have been studies that have characterized innovation in various industries from the perspective of technology, but far fewer in the area of corporate reputation, consumer perception, and intention towards innovations in food products. This research analyses the innovations in the food industry from the perspective of the consumer and provides a conceptual framework of food innovation stages. The study also investigates the relationship between corporate reputation and intention towards food innovation along with the other components of TPB model with an extension of social media engagement. The results from India and US samples confirm that social media engagement have a significant role to play in creating intention to purchase innovative food products. The study compares the US and Indian samples and identifies differences in subjective norms and perceived behavioural control

Under-recording of hospital bleeding events in UK primary care: a linked Clinical Practice Research Datalink and Hospital Episode Statistics study

Laura McDonald,1,* Cormac J Sammon,2,* Mihail Samnaliev,2 Sreeram Ramagopalan1 1Centre for Observational Research and Data Sciences, Bristol-Myers Squibb, Uxbridge, UK; 2PHMR, Berkeley Works, London, UK *These authors contributed equally to this work Background: Primary care databases represent a rich source of data for health care research; however, the quality of recording of secondary care events in these databases is uncertain. This study sought to investigate the completeness of recording of hospital admissions for bleeds in primary care records and explore the impact of incomplete recording on estimates of bleeding risk associated with antithrombotic treatment.Methods: The study population consisted of adults with non-valvular atrial fibrillation who had at least one bleed recorded in either the Clinical Practice Research Datalink (CPRD) or Hospital Episode Statistics (HES) while receiving prescriptions for an oral anticoagulant. The proportion of bleeds recorded in HES that had a corresponding bleed recorded in the subsequent 12 weeks in CPRD was calculated, and factors associated with having a corresponding record were identified. Cox proportional hazards analyses investigating the hazard of subsequent bleeding associated with antithrombotic treatment were carried out using linked CPRD-HES data and using CPRD only data, and the results were compared.Results: Less than 20% of the 14,361 bleeds recorded in the HES data had a corresponding bleed coded in the CPRD in the subsequent 12 weeks. This proportion varied by bleed characteristics, calendar time, day of week of admission (weekday vs weekend) and oral anticoagulant treatment at the time of the bleed. The hazard of subsequent bleeding associated with vitamin K antagonists (VKAs) and antiplatelet agents (APAs) relative to no antithrombotic treatment were similar using the linked primary and secondary care dataset (VKA HRadj 1.06 CI95 0.96–1.16; APA HRadj 1.08 CI95 0.96–1.21) and the unlinked primary care data (VKA HRadj 1.12 CI95 1.01–1.24; APA HRadj 1.06 CI95 0.95–1.20).Conclusion: Secondary care bleeding events are not completely recorded in primary care records and under-recording may be differential with respect to a variety of factors, including antithrombotic treatment. While the impact of under-recording on estimates of the comparative safety of antithrombotic drugs was limited, the extent of the under-recording suggests its potential impact should be considered, and ideally evaluated in future studies utilizing stand-alone primary care data. Keywords: real-world data, data linkage, comparative effectiveness, secondary care, atrial fibrillatio

Estimating the diagnostic accuracy of rheumatoid factor in UK primary care: a study using the clinical practice research datalink

Objective: To investigate the diagnostic accuracy of RF as a test for RA in primary care and its impact on referral times using the Clinical Practice Research Datalink. Methods: We identified all patients with a first RF test recorded in the Clinical Practice Research Datalink between 1 January 2000 and 31 December 2008 and those diagnosed with RA within 2 years of testing. We calculated likelihood ratios (LRs), sensitivity, specificity and predictive values of RF for a diagnosis of RA. We compared time to hospital referral in those testing positive and negative using Kaplan–Meier failure curves and log-rank tests. Results: Of 62 436 first RF tests, 4679 (7.5%) were positive. There were 1753 incident cases of RA, of which 57.8% were seropositive. The positive LR for RF was 9.5 (95% CI 9.0, 10.0) and the negative LR was 0.5 (95% CI 0.4, 0.5). Sensitivity and specificity were 57.8% (95% CI 55.4%, 60.1%) and 93.9% (95% CI 93.7%, 94.1%) and the positive predictive value and negative predictive value were 21.4% (95% CI 20.3%, 22.6%) and 98.7% (95% CI 98.6%, 98.8%), respectively. Median time to first hospital contact after the first RF test in those with seropositive vs seronegative results was 54 days (95% CI 49, 58) vs 150 (95% CI 147, 152). Conclusion: Only 2.8% of patients undergoing RF testing were diagnosed with RA, suggesting that RF is used to screen patients with musculoskeletal symptoms rather than those with more specific features of RA. A positive RF test may be helpful in diagnosing RA in primary care but performs badly in excluding RA and may delay referral. </p