IntroductionAdministrative health data, such as pharmacy claims data, present a valuable resource for conducting pharmacoepidemiological and health services research. Often, data are available for whole populations allowing population level analyses. Moreover, their routine collection ensures that the data reflect health care utilisation in the real-world setting compared to data collected in clinical trials.Setting and methodsThe Irish Health Service Executive-Primary Care Reimbursement Service (HSE-PCRS) community pharmacy claims database is described. The availability of demographic variables and drug-related information is discussed. The strengths and limitations associated using this database for conducting research are presented, in particular, internal and external validity. Examples of recently conducted research using the HSE-PCRS pharmacy claims database are used to illustrate the breadth of its use.Results and conclusionsThe HSE-PCRS national pharmacy claims database is a large, high-quality, valid and accurate data source for measuring drug exposure in specific populations in Ireland. The main limitation is the lack of generalisability for those aged <70 years and the lack of information on indication or outcome.

IntroductionCopayments are intended to decrease third party expenditure on pharmaceuticals, particularly those regarded as less essential. However, copayments are associated with decreased use of all medicines. Publicly insured populations encompass some vulnerable patient groups such as older individuals and low income groups, who may be especially susceptible to medication non-adherence when required to pay. Non-adherence has potential consequences of increased morbidity and costs elsewhere in the system.ObjectiveTo quantify the risk of non-adherence to prescribed medicines in publicly insured populations exposed to copayments.MethodsThe population of interest consisted of cohorts who received public health insurance. The intervention was the introduction of, or an increase, in copayment. The outcome was non-adherence to medications, evaluated using objective measures. Eight electronic databases and the grey literature were systematically searched for relevant articles, along with hand searches of references in review articles and the included studies. Studies were quality appraised using modified EPOC and EHPPH checklists. A random effects model was used to generate the meta-analysis in RevMan v5.1. Statistical heterogeneity was assessed using the I2 test; p>0.1 indicated a lack of heterogeneity.ResultsSeven out of 41 studies met the inclusion criteria. Five studies contributed more than 1 result to the meta-analysis. The meta-analysis included 199, 996 people overall; 74, 236 people in the copayment group and 125,760 people in the non-copayment group. Average age was 71.75years. In the copayment group, (verses the non-copayment group), the odds ratio for non-adherence was 1.11 (95% CI 1.09–1.14; P = <0.00001). An acceptable level of heterogeneity at I2 = 7%, (p = 0.37) was observed.ConclusionThis meta-analysis showed an 11% increased odds of non-adherence to medicines in publicly insured populations where copayments for medicines are necessary. Policy-makers should be wary of potential negative clinical outcomes resulting from non-adherence, and also possible knock-on economic repercussions.

Objective To estimate the incidence and prevalence of resistant hypertension among a UK population treated for hypertension from 1995 to 2015. Design Cohort study. Setting Electronic health records from the UK Clinical Practice Research Datalink in primary care. Participants 1 317 290 users of antihypertensive drugs with a diagnosis of hypertension. Main outcome measures Resistant hypertension was defined as concurrent use of three antihypertensive drugs inclusive of a diuretic, uncontrolled hypertension (≥140/90 mm Hg), and adherence to the prescribed drug regimen, or concurrent use of four antihypertensive drugs inclusive of a diuretic and adherence to the prescribed drug regimen. To determine incidence, the numerator was new cases of resistant hypertension and the denominator was person years of those with treated hypertension and at risk of developing resistant hypertension. To determine prevalence, the numerator was total number of cases with resistant hypertension and the denominator was those with treated hypertension. Prevalence and incidence were age standardised to the 2015 hypertensive population. Results The age standardised incidence of resistant hypertension increased from 0.93 cases per 100 person years (95% confidence interval 0.87 to 1.00) in 1996 to a peak level of 2.07 cases per 100 person years (2.03 to 2.12) in 2004. Incidence then decreased to 0.42 cases per 100 person years (0.40 to 0.44) in 2015. Age standardised prevalence increased from 1.75% (95% confidence interval 1.66% to 1.83%) in 1995 to a peak of 7.76% (7.70% to 7.83%) in 2007. Prevalence then plateaued and subsequently declined to 6.46% (6.38% to 6.54%) in 2015. Compared with patients aged 65-69 years, those aged 80 or more years were more likely to have prevalent resistant hypertension throughout the study period. Conclusions Prevalent resistant hypertension has plateaued and decreased in recent years, consistent with a decrease in incidence from 2004 onwards. Despite this, resistant hypertension is common in the UK hypertensive population. Given the importance of hypertension as a modifiable risk factor for cardiovascular disease, reducing uncontrolled hypertension should remain a population health focus.

Objective To determine the concordance between two methods to measure drug exposure duration from pharmacy claims data. Study design and setting We conducted a cohort study using 2002–2007 US Medicaid data. Initiators of eight drug groups were indentified: statins, metformin, atypical antipsychotics, warfarin, proton pump inhibitors (PPIs), angiotensin converting enzyme (ACE)-inhibitors, non-steroidal anti-inflammatory drugs (ns-NSAIDs) and coxibs. For each patient, we calculated two measures of exposure duration using 1) observed days’ supply available in US pharmacy claims and 2) the World Health Organisation Daily Defined Doses (DDD) methodology. We used Wilcoxon signed rank tests to compare medians and Spearman correlations to assess correlation between the two measures. Results Cohort sizes ranged from 143,885 warfarin users to >3,000,000 ns-NSAID users. Similar median exposure durations were observed for ACE-inhibitors (70days vs. 75days), PPIs (44days vs. 45days) and coxibs (44days vs. 45days). The DDD method overestimated exposure duration for ns-NSAIDs and underestimated for the remaining drug groups, relative to days’ supply. Spearman correlation coefficients ranged from 0.2–0.8. Conclusion Using DDDs to estimate drug exposure duration can result in misclassification. The magnitude of this misclassification might depend on doses used which can vary according to factors such as local prescribing practices, renal function and age.

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ObjectiveInternationally, caesarean section (CS) rates are rising. However, mean rates of CS across providers obscure extremes of CS provision. We aimed to quantify variation between all maternity units in Ireland.MethodsTwo national databases, the National Perinatal Reporting System and the Hospital Inpatient Enquiry Scheme, were used to analyse data for all women delivering singleton births weighing ≥500g. We used multilevel models to examine variation between hospitals in Ireland for elective and emergency CS, adjusted for individual level sociodemographic, clinical and organisational variables. Analyses were subsequently stratified for nullipara and multipara with and without prior CS.ResultsThe national CS rate was 25.6% (range 18.2% ─ 35.1%). This was highest in multipara with prior CS at 86.1% (range 6.9% ─ 100%). The proportion of variation in CS that was attributable to the hospital of birth was 11.1% (95% CI, 6.0 ─ 19.4) for elective CS and 2.9% (95% CI, 1.4 ─ 5.6) for emergency CS, after adjustment. Stratifying across parity group, variation between hospitals was greatest for multipara with prior CS. Both types of CS were predicted by increasing age, prior history of miscarriage or stillbirth, prior CS, antenatal complications and private model of care.ConclusionThe proportion of variation attributable to the hospital was higher for elective CS than emergency CS suggesting that variation is more likely influenced by antenatal decision making than intrapartum decision making. Multipara with prior CS were particularly subject to variability, highlighting a need for consensus on appropriate care in this group.

. It was presented in poster format and won a poster award in the "Adherence" spotlight session. Key Points:1) The main public health insurance scheme in Ireland (GMS) provides primary care to approximately 40% of the population, generally on a means tested basis, but also on the basis of older age.2) Until 2010 prescription medicines were free at the point of access on this scheme. In 2010 each prescription item was made subject to a €0.50 copayment. This was increased to €1.50 per item in 2013.3) We found that both copayments had a larger impact on adherence to less-essential medicines than essential medicines, consistent with the prior literature. 4) Notably, in comparison to other essential medicines, relatively larger reductions in adherence to anti-depressant medicines were observed after each copayment intervention. 5) Further analyses of our results on anti-depressant medicines, in addition to analyses for clinical outcomes and variability according to socio-economic status within the GMS population, would increase our understanding of the wider impact of this copayment policy. 3 Abstract PurposeWe assessed the impact of the introduction of a €0.50 prescription copayment, and its increase to €1.50, on adherence to essential and less-essential medicines in a publicly insured population in Ireland. MethodsWe used a pre-post longitudinal repeated measures design. We included new users of blood pressure lowering, lipid lowering and oral diabetic agents, thyroid hormone, anti-depressants, non-steroidal anti-inflammatory drugs (NSAIDs), Proton Pump Inhibitors/H2 antagonists (PPIs/H2) and anxiolytics/hypnotics. The outcome was change in adherence, measured using proportion of days covered. We used segmented regression with generalised estimating equations to allow for repeated measurements. ResultsSample sizes ranged from 7,145 (thyroid hormone users) to 136,111(NSAID users). The €0.50 copayment was associated with reductions in adherence ranging from -2.1%[95% CI, -2.8 to -1.5] (thyroid hormone) to -8.3%[95% CI, -8.7 to -7.9] (anti-depressants) for essential medicines and reductions of -2%[95% CI, -2.3 to -1.7] (anxiolytics/hypnotics) to -9.5%[95% CI, -9.8 to -9.1] (PPIs/H2) for less-essential medicines. The €1.50 copayment generally resulted in smaller reductions in adherence to essential medicines. Antidepressant medications were the exception with a decrease of -10.0% [95% CI,] after the copayment increase. Larger decreases in adherence were seen for less-essential medicines; the largest was for PPIs/H2 at -13.5% [95% CI, -13.9 to -13.2] after the €1.50 copayment. Conclusion 4Both copayments had a greater impact on adherence to less-essential medicines than essential medicines. The major exception was for anti-depressant medicines. Further research is required to explore heterogeneity across different socio-economic strata and to elicit the impact on clinical outcomes.5

BackgroundOral cancer is a significant public health problem world-wide and exerts high economic, social, psychological, and physical burdens on patients, their families, and on their primary care providers. We set out to describe the changing trends in incidence and survival rates of oral cancer in Ireland between 1994 and 2009.MethodsNational data on incident oral cancers [ICD 10 codes C01-C06] were obtained from the National Cancer Registry Ireland from 1994 to 2009. We estimated annual percentage change (APC) in oral cancer incidence during 1994–2009 using joinpoint regression software (version 4.2.0.2). The lifetime risk of oral cancer to age 79 was estimated using Irish incidence and population data from 2007 to 2009. Survival rates were also examined using Kaplan-Meier curves and Cox proportional hazard models to explore the influence of several demographic/lifestyle covariates with follow-up to end 2012.ResultsData were obtained on 2,147 oral cancer incident cases. Men accounted for two-thirds of oral cancer cases (n = 1,430). Annual rates in men decreased significantly during 1994–2001 (APC = -4.8 %, 95 % CI: −8.7 to −0.7) and then increased moderately (APC = 2.3 %, 95 % CI: −0.9 to 5.6). In contrast, annual incidence increased significantly in women throughout the study period (APC = 3.2 %, 95 % CI: 1.9 to 4.6). There was an elevated risk of death among oral cancer patients who were: older than 60 years of age; smokers; unemployed or retired; those living in the most deprived areas; and those whose tumour was sited in the base of the tongue. Being married and diagnosed in more recent years were associated with reduced risk of death.ConclusionOral cancer increased significantly in both sexes between 1999 and 2009 in Ireland. Our analyses demonstrate the influence of measured factors such as smoking, time of diagnosis and age on observed trends. Unmeasured factors such as alcohol use, HPV and dietary factors may also be contributing to increased trends. Several of these are modifiable risk factors which are crucial for informing public health policies, and thus more research is needed.