Aspects of statin prescribing in Norwegian counties with high, average and low statin consumption - an individual-level prescription database study

Prevalence and initiation of statin therapy in the oldest old-a longitudinal population-based study

Purpose

To investigate the prevalence and initiation of statins as well as treatment intensity in the oldest old, with younger olds as a reference.

Methods

A population-based cohort was used, including record-linked data from the Total Population Register, the Swedish Prescribed Drug Register, and the Swedish Patient Register. In each year over the study period (2009–2015), statin use was described in individuals 85 years or older and 65–84 years of age, and initiation rates were calculated among individuals with no statin treatment during a preceding 3-year period.

Results

A total of 1,764,836 individuals ≥ 65 years in 2009, increasing to 2,022,764 in 2015, were included in the analyses. In individuals 85 years or older, the prevalence of statin therapy increased from 11% in 2009 to 16% in 2015, the corresponding initiation rates being 1.3% and 1.7%, respectively. Corresponding prevalence and incidence figures in 65–84-year-olds were 23 to 25% and 3.0 to 3.3%, respectively. Overall, the proportion of individuals initiating statin with high-intensity treatment (atorvastatin ≥ 40 mg or rosuvastatin ≥ 20 mg) in the oldest old increased from 1 to 36% during the study period, and a similar increase was seen in the younger age group. Over the study years, the presence of an established indication for statin treatment varied between 70 and 76% in the oldest old and between 30 and 39% in the younger olds.

Conclusion

Prevalence and initiation of statin therapy are increasing among the oldest old, despite the fact that randomized controlled trials focusing on this age group are lacking and safety signals are difficult to detect.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-022-03343-w.

Use of Statins in Kidney Transplant Recipients in Norway

Kidney transplant recipients (KTRs) experience increased risk of cardiovascular disease. Guidelines recommend HMG-CoA reductase inhibitor (statin) therapy when tolerated. We aimed to study changes in the prescription of statins and patients’ adherence to treatment over time. A population-based observational study utilizing linked data from the Norwegian Renal Registry (national coverage of 99.9%) and the Norwegian Prescription Database was performed. Data from a total of 2250 first KTRs were included (mean age—54 years, 69% men). Dispensed prescriptions of statins and immunosuppressants for the period 2004–2016 for all first KTRs engrafted in the period 2005–2015 were analyzed. Seventy-two percent received statins the first year after kidney transplantation and the proportion increased with age. The proportion receiving a statin varied according to the time frame of transplantation (77% in 2005–2010 vs. 66% in 2012–2015). Among new users of statins, 82% of the patients were adherent both the second and third year after kidney transplantation, while the corresponding figure for those already receiving statins before transplantation was 97%. Statin continuation rates in KTRs were high. In conclusion, our findings show a slightly lower overall proportion of patients receiving statins after kidney transplants than the national target level of 80%. The proportion of statin users increased with the age of the KTRs but showed a decreasing trend as time progressed.

Implications of a defined daily dose fixed database for drug utilization research studies: The case of statins in Portugal

AIMS

Given the discrepancies between PDDs (prescribed daily doses) and DDDs (defined daily doses), we aimed to assess the extent of error in the results of an 18-year population-level study on statin utilization in Portugal.

METHODS

The Portuguese regulatory agency provided data for the period 2000-2018 on statin dispensing (C10AA). The DDDs were gathered from the ATC/DDD database. DDDs were calculated by the DDD year-by-year approach (DDD_YEAR ) and by the DDD last-year approach (DDD_LAST ). PDDs were calculated according to the year-by-year approach (PDD_YEAR ). Statin annual utilization rates per 1000 inhabitants per day were also calculated. Percent errors were calculated for PDD_YEAR and DDD_YEAR units.

RESULTS

The DDD_YEAR approach revealed decreases in the consumption of atorvastatin, fluvastatin, lovastatin, pravastatin and simvastatin in 2009, when their DDD was modified. Conversely, the results from both DDD_LAST and PDD_YEAR approaches indicated gradual changes in the actual consumption of all statins in Portugal. Before 2009, atorvastatin, pravastatin and simvastatin utilization was greatly overestimated by DDD_YEAR /1000 inhabitants/day. The average dose of lovastatin prescribed in the past 18 years (20 mg) was below the assigned DDDs during the study period, varying from 30 mg to 45 mg. Conversely, the PDD for fluvastatin was above the DDD values (ranging from 40 mg in 2000 to 70 mg in 2016). For atorvastatin, pravastatin and simvastatin, national PDDs were above the assigned DDD until the DDD modification in 2009.

CONCLUSIONS

A more dynamic system, based on national and annually updated DDDs, should be able to reduce discrepancies between DDDs and PDDs and the bias in utilization studies.

Time trends analysis of statin prescription prevalence, therapy initiation, dose intensity, and utilization from the hospital information system of Jinshan Hospital, Shanghai (2012-2018)

BACKGROUND

Statin remains a mainstay in the prevention and treatment of cardiovascular diseases. Statin utilization has evolved over time in many countries, but data on this topic from China are quite limited. This study aimed to investigate the changing trends of statins prescription, as well as detail the statin utilization through a successive longitudinal study.

METHODS

The prescription database was established based on electronic health records retrieved from the hospital information system of Jinshan Hospital, Fudan University from January 2012 to December 2018 in Shanghai, China. The prescription rates and proportions of different statin types and doses among all patients were examined. Sub-analyses were performed when stratifying the patients by age, gender, dose intensity, and preventative intervention.

RESULTS

During the study period, a total of 51,083 patients, who were prescribed for statins, were included in this study (mean [SD] age, 59.78 [±13.16] years; 53.60% male, n = 27, 378). The overall statins prescription rate in which patients increased from 2012 (1.24, 95% CI: 1.21-1.27%) to 2018 (3.16, 95% CI: 3.11-3.20%), P < 0.001. Over 90% of patients were given a moderate dose of statins. Patients with a history of coronary and cerebrovascular events (over 32%) were more likely to be prescribed with statins for preventative intervention. Furthermore, our study has witnessed a significant rise in statin therapy in primary and secondary prevention.

CONCLUSIONS

In conclusion, statins were frequently prescribed and steadily increased over time in our study period. There were also changes in statin drug choices and dosages. A coordinated effort among the patient, clinical pharmacist, stakeholders and health system is still needed to improve statin utilization in clinical practice in the future.

Inequalities in prescription rates of anti-osteoporosis drugs in primary care in England: A practice-level prescribing data analysis in 2013-2018

OBJECTIVE

To investigate potential variations in prescription rates of anti-osteoporosis drugs at the general practitioner (GP) practice level in England, analysing associations of prescription rates with key demographic and socio-economic variables, and its evolution over time.

METHODS

A retrospective database analysis was conducted using prescription data from all GP practices in England between April 2013 and September 2018. Potential associations between prescription rates and other variables (sex, age, ethnicity, rural-urban classification and income deprivation) were analysed using mixed-effects Poisson regressions and concentration indices.

RESULTS

Alendronic acid was the most frequently prescribed anti-osteoporosis drug. Exploratory and regression analyses showed the association between GP prescriptions and the characteristics of the population they serve. Income deprivation had a statistically significant and negative effect on prescription levels of alendronic acid, denosumab, ibandronic acid and risedronate sodium. Since 2013, denosumab prescriptions exhibited a steep surge in the least income-deprived areas, compared with a modest rise in the most income-deprived areas. Concentration indices indicated a disproportionate concentration of denosumab and, to a lesser extent, ibandronic acid prescriptions among the least income-deprived. The analyses demonstrated that different prescribing behaviours may exist across GPs according to the Clinical Commissioning Group (CCG) to which they belong.

CONCLUSIONS

Variation in the prescription of anti-osteoporosis drugs exists across GPs and CCGs in England, this being more prominent for certain drugs (e.g. denosumab) compared with others (e.g. alendronic acid). Inequalities exist in English primary healthcare and we advocate our findings could support the efforts of decision-makers towards a more equitable system.

Prescriber Variation in Relation to Prescribing Trends within the Preferred Drugs Initiative in Ireland (2012-2015): An Interrupted Time-Series Study Using Latent Curve Models

OBJECTIVES

To examine the impact of the Preferred Drugs Initiative (PDI), an Irish health policy aimed at reducing prescribing variation.

DESIGN

Interrupted time series spanning 2012 to 2015.

SETTING

Health Service Executive pharmacy claims data for General Medical Services (GMS) patients, approximately 40% of the Irish population.

PARTICIPANTS

Prescribers issuing preferred drug group items to GMS adults before and after PDI guidelines.

PRIMARY OUTCOME

The percentage coverage of PDI medications within each drug class per calendar quarter per prescriber.

METHODS

Latent curve models with structured residuals (LCM-SRs) were used to model coverage of the preferred drugs over time. The number of GMS adults receiving medication and the percentage who were 65 years and older at the start of the study were included as covariates.

RESULTS

In the quarter following PDI guidelines, coverage of the preferred drugs increased most in absolute terms for proton pump inhibitors (PPIs) (1.50% [SE 0.15], P < 0.001) and selective and norepinephrine reuptake inhibitors (SNRIs) (1.17% [SE 0.26], P < 0.001). Variation between prescribers remained relatively unchanged and increased for urology medications. Prescribers who increased coverage of the preferred PPI also increased coverage of the preferred statin immediately following guidelines (correlation 0.47 [SE 0.13], P < 0.001). Where guidelines were disseminated simultaneously, coverage of one preferred drug did not significantly predict coverage of the other preferred drug in the next calendar quarter. Prescribing of preferred drugs was not moderated by prescriber-level factors.

CONCLUSIONS

Modest changes in prescribing of the preferred drugs have been observed over the course of the PDI. However, the guidelines have had little impact in reducing variation between prescribers. Further strategies may be necessary to reduce variation in clinical practice and enhance patient care.

Does pregnancy alter life-course lipid trajectories? Evidence from the HUNT Study in Norway

We examined the association between pregnancy and life-course lipid trajectories. Linked data from the Nord-Trøndelag Health Study and the Medical Birth Registry of Norway yielded 19,987 parous and 1,625 nulliparous women. Using mixed-effects spline models, we estimated differences in nonfasting lipid levels from before to after first birth in parous women and between parous and nulliparous women. HDL cholesterol (HDL-C) dropped by -4.2 mg/dl (95% CI: -5.0, -3.3) from before to after first birth in adjusted models, a 7% change, and the total cholesterol (TC) to HDL-C ratio increased by 0.18 (95% CI: 0.11, 0.25), with no change in non-HDL-C or triglycerides. Changes in HDL-C and the TC/HDL-C ratio associated with pregnancy persisted for decades, leading to altered life-course lipid trajectories. For example, parous women had a lower HDL-C than nulliparous women at the age of 50 years (-1.4 mg/dl; 95% CI: -2.3, -0.4). Adverse changes in lipids were greatest after first birth, with small changes after subsequent births, and were larger in women who did not breastfeed. Findings suggest that pregnancy is associated with long-lasting adverse changes in HDL-C, potentially setting parous women on a more atherogenic trajectory than prior to pregnancy.

A probabilistic bias analysis for misclassified categorical exposures, with application to oral anti-hyperglycaemic drugs

PURPOSE

The effect of drug exposure misclassification generally receives little attention in pharmacoepidemiological research. In this paper, we illustrate a probabilistic bias analysis approach for misclassified categorical exposures and apply it in a database study of oral anti-hyperglycaemic drugs (OADs).

METHODS

A cohort study based on the Health Search Database general-practice database was carried out by including 12 640 adult (≥40 years) patients newly treated with OADs during 2003-2010. The proportion of days covered by OADs prescriptions during the first year of follow-up was evaluated for each individual, either by means of the prescribed daily dose or the defined daily dose. The effect of misclassification on hypothetical OAD-outcome association profiles was assessed through the proposed probabilistic bias analysis approach, taking advantage of available exposure validation data.

RESULTS

During the first year of follow-up, the average (SD) number of months with OADs available was 7 (4) months and 5 (3) months according to the prescribed daily dose and defined daily dose metrics, respectively. Probabilistic bias analysis results based on validation data suggest that the effect of misclassification is complex, as conventional exposure-outcome association estimates may be of greater or lower magnitude than their misclassification-adjusted values.

CONCLUSIONS

Misclassification should be taken into account in database studies on the safety of prescribed medications. To this aim, investigators should take advantage of external exposure validation data in sensitivity analysis approaches such as ours. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of drug price reduction and prescribing restrictions on expenditures and utilisation of antihypertensive drugs in Korea

OBJECTIVES

To evaluate the quantitative effects of the drug price reduction on pharmaceutical expenditures and the new guidelines to restrict prescribing on drug utilisation for antihypertensive drugs.

DESIGN

We used an interrupted time series design with the National patient sample data of Health Insurance Review and Assessment Service in South Korea.

METHODS

54,295 participants who were with primary hypertension from the National patient sample data of Health Insurance Review and Assessment Service were included. The study period was from March 2011 to December 2013. The dependent variables were antihypertensive drug costs, antihypertensive drug cost per prescribing day, daily drug utilisation, average number of drugs per month, percentage of original drugs per prescription, drug overutilisation and prohibited combinations. Segmented regression analysis was used.

RESULTS

The drug price reduction reduced expenditure (US$-1.51, -10.2%), and the new guidelines reduced expenditures even more (US$-2.13; -16.2%). These policies saved US$4.22 (28%) of antihypertensive drug costs per patient in December 2013 compared to March 2012. Drug price reduction policy was introduced in April 2012. We established the policy effect by comparing it before (March 2012) with after(21 months later-December 2012). The effects of the guidelines decreased expenditures, daily drug utilisation and the average number of drugs per month more than did the drug price reduction.

CONCLUSIONS

Both policies saved money. The guidelines were more effective over time and had fewer side effects such as increasing daily drug utilisation and number of drugs than the effects of drug price reduction.

Quality and efficiency of statin prescribing across countries with a special focus on South Africa: findings and future implications

INTRODUCTION

Statins are recommended first-line treatment for hyperlipidemia, with published studies suggesting limited differences between them. However, there are reports of under-dosing. South Africa has introduced measures to enhance generic utilization. Part one documents prescribed doses of statins in 2011. Part two determines the extent of generics versus originator and single-sourced statins in 2011 and their costs.

RESULTS

Underdosing of simvastatin in 2011 with average prescribed dose of 23.7 mg; however, not for atorvastatin (20.91 mg) or rosuvastatin (15.02 mg). High utilization of generics versus originators at 93-99% for atorvastatin and simvastatin, with limited utilization of single-sourced statins (22% of total statins - defined daily dose basis), mirroring Netherlands, Sweden and UK. Generics priced 33-51% below originator prices.

DISCUSSION

Opportunity to increase simvastatin dosing through education, prescribing targets and incentives. Opportunity to lower generic prices with generic simvastatin 96-98% below single-sourced prices in some European countries.

Statin use and survival following glioblastoma multiforme

AIM

While some studies indicate a potential chemopreventive effect of statin use on the risk of glioma, the effect of statins on the prognosis of brain tumours has not yet been examined. We thus conducted a cohort study evaluating the influence of statin use on survival in patients with glioblastoma multiforme (GBM).

METHODS

We identified 1562 patients diagnosed with GBM during 2000-2009 from the Danish Cancer Registry and linked this cohort to Danish nationwide demographic and health registries. Within the GBM cohort, each patient recorded as using statins prior to diagnosis (defined as ≥ 2 redeemed prescriptions) was matched to two statin non-users (<2 redeemed prescriptions) by propensity scores based on age, gender, year of diagnosis, comorbidity, and use of selected drugs. Cox proportional hazard models were used to compute hazard ratios (HRs) and 95% confidence intervals (CI) for all-cause death associated with prediagnostic statin use.

RESULTS

A total of 339 GBM patients were included in the analyses. Of these, 325 died during median follow-up of 6.9 months (interquartile range: 3.8-13.4 months). Prediagnostic statin use was associated with a reduced HR of death (0.79; 95% CI: 0.63-1.00). The HRs decreased with increasing duration or intensity of prediagnostic statin use [long-term (≥ 5 years) statin use: HR 0.75 (95% CI: 0.47-1.20); high-intensity statin use: HR 0.66 (95% CI: 0.44-0.98)]. Additional adjustment for oncotherapeutic modalities yielded similar results (overall HR 0.80, 95% CI: 0.63-1.01).

CONCLUSION

Long-term prediagnostic statin use may improve survival following GBM.

Hospital statistics for antibiotics: defined versus prescribed daily dose

PURPOSE

Defined daily doses (DDD) are widely used as a unit to measure drug use in hospital and community settings. However, discrepancies exist between DDD and actual prescribed daily dose (PDD). The present study aims at estimating an alternative PDD (PDD-proxy) to calculate rates of systemic antibiotic consumption and to compare these results with those obtained using DDD.

METHODS

The study considered a 9-year period (2004-2012) and included the 17 Health Trusts (HTs) in the Emilia-Romagna Region, Italy. Drugs under study were antibacterials for systemic use (group J01). Data were obtained from the database for hospital drug prescription of Emilia-Romagna Region. The PDD-proxy was estimated by averaging the doses of antibiotic prescriptions from a point prevalence survey for healthcare-associated infections and antimicrobial use, conducted in Emilia-Romagna hospitals in 2012.

RESULTS

Significant discrepancies between DDD and PDD were observed, especially for some antibiotics, resulting in DDD rates that were systematically higher than PDD-proxy rates. In 2012, HT median rates of antibiotic consumption were 90 DDD/100 bed days and 70 PDD-proxy/100 bed-days. However, PDD-proxy and DDD rates showed comparable trends within HTs, although some HTs ranked differently when one or the other measure was used. Interquartile ranges of DDD rates were systematically wider than those of PDD-proxy rates in most years in the period of interest.

CONCLUSIONS

Comparison of HT antibiotic consumption using DDDs may artificially increase observed differences and affect the true HT ranking. Therefore, an additional unit of measurement is useful for in-depth analysis at the local level.

A retrospective cohort study of the potency of lipid-lowering therapy and race-gender differences in LDL cholesterol control

BACKGROUND

Reasons for race and gender differences in controlling elevated low density lipoprotein (LDL) cholesterol may be related to variations in prescribed lipid-lowering therapy. We examined the effect of lipid-lowering drug treatment and potency on time until LDL control for black and white women and men with a baseline elevated LDL.

METHODS

We studied 3,484 older hypertensive patients with dyslipidemia in 6 primary care practices over a 4-year timeframe. Potency of lipid-lowering drugs calculated for each treated day and summed to assess total potency for at least 6 and up to 24 months. Cox models of time to LDL control within two years and logistic regression models of control within 6 months by race-gender adjust for: demographics, clinical, health care delivery, primary/specialty care, LDL measurement, and drug potency.

RESULTS

Time to LDL control decreased as lipid-lowering drug potency increased (P < 0.001). Black women (N = 1,440) received the highest potency therapy (P < 0.001) yet were less likely to achieve LDL control than white men (N = 717) (fully adjusted hazard ratio [HR] 0.66 [95% CI 0.56-0.78]). Black men (N = 666) and white women (N = 661) also had lower adjusted HRs of LDL control (0.82 [95% CI 0.69, 0.98] and 0.75 [95% CI 0.64-0.88], respectively) than white men. Logistic regression models of LDL control by 6 months and other sensitivity models affirmed these results.

CONCLUSIONS

Black women and, to a lesser extent, black men and white women were less likely to achieve LDL control than white men after accounting for lipid-lowering drug potency as well as diverse patient and provider factors. Future work should focus on the contributions of medication adherence and response to treatment to these clinically important differences.

Discrepancies between prescribed and defined daily doses: a matter of patients or drug classes?

Purpose

Defined daily doses (DDD) are used for the measurement of drug utilisation. The aim of the study was to analyse whether differences between DDD and prescribed daily doses (PDD) exist for relevant drug classes such as antihypertensive drugs and, if so, whether they primarily depend on drug classes or patient-related factors.

Methods

Using the data of a large German statutory health insurance scheme, we analysed continuous prescriptions for the following antihypertensive drug classes: thiazide diuretics, beta-blockers, dihydropyridine calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin-II receptor blockers (ARBs). We summed the doses of all dispensed drugs per person during a defined time frame. We calculated the PDD (= total dose divided by the number of days) and expressed them as the PDD:DDD ratio (= amount of DDD per day and person).

Results

During the study period, 149,704 patients continuously received an antihypertensive medication. The average PDD:DDD ratio ranged from 0.84 (beta-blockers) to 1.88 (ARBs) and 2.17 (ACEIs). The average prescribed dosage of each drug class remained unchanged, even if the patients had previously received another antihypertensive drug with another PDD:DDD ratio. For example, if patients were switched from a beta-blocker to an ACEI, the PDD:DDD ratio increased, on average, from 0.79 to 2.17. Vice versa, the ratio decreased for patients with a drug change from an ACEI to a beta-blocker from 2.06 to 0.75.

Conclusions

Even large differences between DDD and PDD seem to be a matter of drug classes and not primarily of patient characteristics.

Regional variation and adherence to guidelines for drug treatment of asthma

AIMS

To describe the utilization of antiasthmatic drugs in Sweden and to explore regional variations in drug utilization and adherence to guidelines for rational drug prescribing of antiasthmatics and their rationale.

METHODS

Data on antiasthmatic drugs dispensed between July 2005 and December 2008 to all Swedish citizens aged between 18 and 44 years were obtained from the Swedish National Prescribed Drug Register. The period prevalence was determined by analyzing the number of users/1000 inhabitants, and the incidence by analyzing the number of new users after an 18-month drug-free wash-out period. Three drug-related indicators were used to assess the adherence to guidelines. All measures were analyzed by gender and region.

RESULTS

A total of 161,000 patients were dispensed antiasthmatics in 2007, corresponding to a prevalence of 4 and 6% among men and women, respectively; the incidence rates were 2 and 3%, respectively. The total drug utilization and adherence to guidelines varied between regions. The total drug expenditures of antiastmatics were 258 million SEK (28 million euro), with fixed dose combinations accounting for 46% of the expenditure. No relation was found between models for allocating prescribing budgets or clear Drug and Therapeutics Committee recommendations and adherence to guidelines.

CONCLUSION

There are large regional variations in the utilization of antiasthmatics between Swedish regions, with substantial room for improvement in the adherence to guidelines. New methods of influencing physician behavior may be needed in the future to enhance adherence.