Routinely stored information on healthcare utilisation in everyday clinical practice has proliferated over the past several decades. There is, however, some reluctance on the part of many health ...professionals to use observational data to support healthcare decisions, especially when data are derived from large databases. Challenges in conducting observational studies based on electronic databases include concern about the adequacy of study design and methods to minimise the effect of both misclassifications (in the absence of direct assessments of exposure and outcome validity) and confounding (in the absence of randomisation). This paper points out issues that may compromise the validity of such studies, and approaches to managing analytic challenges. First, strategies of sampling within a large cohort, as an alternative to analysing the full cohort, will be presented. Second, methods for controlling outcome and exposure misclassifications will be described. Third, several techniques that take into account both measured and unmeasured confounders will also be presented. Fourth, some considerations regarding random uncertainty in the framework of observational studies using healthcare utilisation data will be discussed. Finally, some recommendations for good research practice are listed in this paper. The aim is to provide researchers with a methodological framework, while commenting on the value of new techniques for more advanced users.
Blood pressure (BP) control in patients with hypertension is variable worldwide, and in general, it results largely unsatisfactory. Factors responsible for this phenomenon include insufficient ...national cardiovascular healthcare policies for prevention, poor patient compliance with prescribed treatment schedules, and the reluctance of physicians to modify treatment strategies when BP is still elevated, that is, the so-called therapeutic inertia. A further important factor favoring poor BP control is the limited use of combination drug treatment, despite evidence of its superior ability to control BP in patients with difficult-to-treat hypertension. In addition, combination treatment allows to achieve BP control more easily (and more quickly) as compared with monotherapy. This article, after briefly examining the main features of BP control, will review the importance in the treatment of hypertension of the drug combination strategy, based on the recommendations of the 2018 European Society of Cardiology/European Society of Hypertension guidelines. Empahsis will be given to the drug combination treatment as first step of the antihypertensive therapeutic intervention. The potential drawbacks and barriers to combination drug treatment as initial therapeutic strategy will also be briefly discussed.
Guidelines support use of drug combinations in most hypertensive patients, and recently treatment initiation with two drugs has been also recommended. However, limited evidence is available on ...whether this leads to greater cardiovascular (CV) protection compared to initial monotherapy.
Using the healthcare utilization database of the Lombardy Region (Italy), the 44 534 residents of the region (age 40-80 years) who in 2010 started treatment with one antihypertensive drug (n = 37 078) or a two-drug fixed-dose combination (FDC, n = 7456) were followed for 1 year after treatment initiation to compare the risk of hospitalization for CV disease associated with the two treatment strategies. To limit the confounding associated with non-randomized between-group comparisons, data were also analysed by: (i) matching the two groups by the high-dimensional propensity score (HDPS) and (ii) comparing, in patients experiencing one or more CV events (n = 2212), the CV event incidence during subperiods in which patients were prescribed mono- or FDC therapy (self-controlled case series design). Compared to initial monotherapy, patients on initial FDC therapy showed a reduced 1 year risk of hospitalization for any CV event (-21%, P < 0.01). This was the case also when groups were compared according to the HDPS analysis (-15%, P < 0.05). Finally, in patients experiencing CV events, the event incidence was much less when, during the 1 year follow-up, they were under FDC therapy than under monotherapy (-56%, P < 0.01). The reduced risk of hospitalization was always significant for ischaemic heart disease and new onset atrial fibrillation, and included hospitalization for cerebrovascular disease and heart failure when monotherapy and FDC therapy were compared within patients.
In a real-life setting, a comparison of the incidence of early CV events during antihypertensive monotherapy and FDC shows that the latter strategy leads to a more effective CV protection. This scores in favour of a two-drug FDC strategy as first step in the hypertensive population.
Abstract Objectives Protopathic bias is a systematic error which occurs when measured exposure status may be affected by the latent onset of the target outcome. In this article, we aimed to discuss ...the benefits and drawbacks of the lag-time approach to address this type of bias. Study Design and Setting The lag-time approach consists in excluding from exposure assessment the period immediately preceding the outcome detection date. With the help of simple causal diagrams, we illustrate the rationale and limitations of such strategy. The lag-time approach was illustrated in a case-crossover study, based on the health care utilization databases of the Italian Lombardy Region, on the real-world effectiveness of some respiratory drugs (exposure) in preventing asthma exacerbations (outcome). Results A total of 7,300 of patients who were admitted to an emergency department (ED) for asthma during 2010–2012 (cases) were included. Use (vs. nonuse) of short-acting beta-agonists (SABAs, an asthma reliever medication) during the 90 days before the ED admission date was associated with an increased risk of the outcome odds ratio (OR): 1.95; 95% confidence interval (CI): 1.72, 2.22. This paradoxical finding may be explained by protopathic bias, as SABA use prior the ED admission may be affected by preceding respiratory distress. Indeed, when a 120-day period preceding the ED admission was ignored from drug exposure assessment (lag time), SABAs were found to be associated with a reduced risk of the outcome (OR: 0.81; 95% CI: 0.84, 0.92), as expected. Conclusions The lag-time approach can be a useful strategy to circumvent protopathic bias in observational studies.
Abstract
Aims
To evaluate the long-term reproducibility of masked (MUCH) and white-coat uncontrolled hypertension (WUCH), an information crucial for determining the long-term prognostic impact of ...these conditions.
Methods and results
Reproducibility of MUCH and WUCH was assessed in 1664 hypertensive patients recruited for the European Lacidipine Study on Atherosclerosis and treated with atenolol or lacidipine (±additional drugs) during a 4-year period. Office and 24 h blood pressure (BP) was measured at baseline and every year during treatment, allowing repeated classification of either condition. After 1 year of treatment 21.1% and 17.8% of the patients were classified as MUCH and WUCH, respectively. For both conditions the prevalence was similar in the following years, although with a large change in patients composition because only about 1/3 of patients classified as MUCH or WUCH at one set of office and ambulatory BP measurements maintained the same classification at a subsequent set of measurements. In only 4.5% and 6.2% MUCH and WUCH persisted throughout the treatment period. MUCH and WUCH reproducibility was worse than that of patients showing control or lack of control of both office and ambulatory BP, i.e. controlled and uncontrolled hypertension, respectively.
Conclusion
Both MUCH and WUCH display poor reproducibility over time. This should be taken into account in studies assessing the long-term prognostic value of these conditions based on only one set of BP measurements.
The effect of compliance with antihypertensive medications on the risk of cardiovascular outcomes in a population without a known history of cardiovascular disease has been addressed by a large ...population-based prospective, cohort study carried out by linking Italian administrative databases.
The cohort of 242 594 patients aged 18 years or older, residents in the Italian Lombardy Region, who were newly treated for hypertension during 2000-2001, was followed from index prescription until 2007. During this period patients who experienced a hospitalization for coronary or cerebrovascular disease were identified (outcome). Exposure to antihypertensive drugs from index prescription until the date of hospitalization or censoring was assessed. Proportional hazards models were fitted to assess the association between persistence on and adherence with antihypertensive drug therapy and outcome. Data were adjusted for several covariates.
During an average follow-up of 6 years, 12 016 members of the cohort experienced the outcome. Compared with patients who experienced at least one episode of treatment discontinuation, those who continued treatment had a 37% reduced risk of cardiovascular outcomes (95% confidence interval 34-40%). Compared with patients who had very low drug coverage (proportion of days covered ≤ 25%), those at intermediate (from 51 to 75%) and high coverage (>75%) had risk reductions of 20% (16-24%) and 25% (20-29%), respectively. Similar effects were observed when coronary and cerebrovascular events were considered separately.
In the real life setting, fulfillment compliance with antihypertensive medications is effective in the primary prevention of cardiovascular outcomes.
Objectives
To evaluate the association between number of days with delirium and 6‐month mortality in elderly adults after hip fracture surgery.
Design
Prospective cohort study with 6‐month follow‐up.
...Setting
Orthogeriatric Unit (OGU).
Participants
Individuals (mean age = 84.3 ± 6.4) admitted to the OGU between October 2011 and April 2013 with hip fracture (N = 199).
Measurements
Postoperative delirium (POD) was assessed daily using the Confusion Assessment Method algorithm and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, criteria. Multivariable Cox regression models were used to evaluate the association between POD of and 6‐month mortality after surgery, after adjustment for covariates including age, prefracture residence, Katz activity of daily living score, New Mobility score, diagnosis of prefracture dementia, American Society of Anesthesiologists score, albumin serum levels, Charlson Comorbidity Index, and length of OGU stay.
Results
Fifty‐seven participants (28.6%) developed POD. In the 6‐month period after surgery, 35 (17.6%) participants died: 16 of 57 (28.1%) with POD and 19/ of 142 (13.4%) with no POD. The average duration of POD was 2.0 ± 3.2 days for participants who died and 0.7 ± 1.8 days for those who survived (P < .001). After adjusting for covariates, each day of POD in the OGU increased the hazard of dying at 6 months by 17% (hazard ratio = 1.17, 95% confidence interval = 1.07–1.28).
Conclusion
In older adults undergoing hip fracture surgery, duration of POD is an important prognostic factor for 6‐month mortality. Efforts to reduce duration of POD are therefore crucial for these individuals.
It is still debated whether prolonged use of proton pump inhibitors (PPIs) might affect metabolic health.
To investigate the relationship between prolonged use of PPIs and the risk of developing ...diabetes.
We performed a case-control study nested into a cohort of 777 420 patients newly treated with PPIs between 2010 and 2015 in Lombardy, Italy. A total of 50 535 people diagnosed with diabetes until 2020 were matched with an equal number of controls that were randomly selected from the cohort members according to age, sex, and clinical status. Exposure to treatment with PPIs was assessed in case-control pairs based on time of therapy. A conditional logistic regression model was fitted to estimate the odds ratios and 95% CIs for the exposure-outcome association, after adjusting for several covariates. Sensitivity analyses were performed to evaluate the robustness of our findings.
Compared with patients who used PPIs for < 8 weeks, higher odds of diabetes of 19% (95% CI, 15-24), 43% (38-49), and 56% (49-64) were observed among those who used PPIs for between 8 weeks and 6 months, 6 months and 2 years, and > 2 years, respectively. The results were consistent when analyses were stratified according to age, sex, and clinical profile, with higher odds ratios being found in younger patients and those with worse clinical complexity. Sensitivity analyses revealed that the association was consistent and robust.
Regular and prolonged use of PPIs is associated with a higher risk of diabetes. Physicians should therefore avoid unnecessary prescription of this class of drugs, particularly for long-term use.
Care pathways are increasingly being used to enhance the quality of care and optimize the use of resources for health care. Nevertheless, recommendations regarding the sequence of care are mostly ...based on consensus-based decisions as there is a lack of evidence on effective treatment sequences. In a real-world setting, classical statistical tools were insufficient to consider a phenomenon with such high variability adequately and have to be integrated with novel data mining techniques suitable for identifying patterns in complex data structures. Data-driven techniques can potentially support empirically identifying effective care sequences by extracting them from data collected routinely. The purpose of this study is to perform a state sequence analysis (SSA) to identify different patterns of treatment and to asses whether sequence analysis may be a useful tool for profiling patients according to the treatment pattern.
The clinical application that motivated the study of this method concerns the mental health field. In fact, the care pathways of patients affected by severe mental disorders often do not correspond to the standards required by the guidelines in this field. In particular, we analyzed patients with schizophrenic disorders (i.e., schizophrenia, schizotypal or delusional disorders) using administrative data from 2015 to 2018 from Lombardy Region. This methodology considers the patient's therapeutic path as a conceptual unit, composed of a succession of different states, and we show how SSA can be used to describe longitudinal patient status.
We define the states to be the weekly coverage of different treatments (psychiatric visits, psychosocial interventions, and anti-psychotic drugs), and we use the longest common subsequences (dis)similarity measure to compare and cluster the sequences. We obtained three different clusters with very different patterns of treatments.
This kind of information, such as common patterns of care that allowed us to risk profile patients, can provide health policymakers an opportunity to plan optimum and individualized patient care by allocating appropriate resources, analyzing trends in the health status of a population, and finding the risk factors that can be leveraged to prevent the decline of mental health status at the population level.
Abstract Background Single-pill combination (SPC) of three antihypertensive drugs has been shown to improve adherence to therapy compared with free combinations, but little is known about its ...long-term costs and health consequences. This study aimed to evaluate the lifetime cost-effectiveness profile of a three-drug SPC of an angiotensin-converting enzyme inhibitor, a calcium-channel blocker, and a diuretic vs the corresponding two-pill administration (a two-drug SPC plus a third drug separately) from the Italian payer perspective. Methods A cost-effectiveness analysis was conducted using multi-state semi-Markov modeling and microsimulation. Using the healthcare utilization database of the Lombardy Region (Italy), 30,172 and 65,817 patients aged ≥ 40 years who initiated SPC and two-pill combination, respectively, between 2015 and 2018 were identified. The observation period extended from the date of the first drug dispensation until death, emigration, or December 31, 2019. Disease and cost models were parametrized using the study cohort, and a lifetime microsimulation was applied to project costs and life expectancy for the compared strategies, assigning each of them to each cohort member. Costs and life-years gained were discounted by 3%. Probabilistic sensitivity analysis with 1,000 samples was performed to address parameter uncertainty. Results Compared with the two-pill combination, the SPC increased life expectancy by 0.86 years (95% confidence interval CI 0.61–1.14), with a mean cost differential of -€12 (95% CI -9,719–8,131), making it the dominant strategy (ICER = -14, 95% CI -€15,871–€7,113). The cost reduction associated with the SPC was primarily driven by savings in hospitalization costs, amounting to €1,850 (95% CI 17–7,813) and €2,027 (95% CI 19–8,603) for patients treated with the SPC and two-pill combination, respectively. Conversely, drug costs were higher for the SPC (€3,848, 95% CI 574–10,640 vs. €3,710, 95% CI 263–11,955). The cost-effectiveness profile did not significantly change according to age, sex, and clinical status. Conclusions The SPC was projected to be cost-effective compared with the two-pill combination at almost all reasonable willingness-to-pay thresholds. As it is currently prescribed to only a few patients, the widespread use of this strategy could result in benefits for both patients and the healthcare system.
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