Use of 5-alpha reductase inhibitors and risk of gastrointestinal cancers in men with benign prostatic hyperplasia: A population-based cohort study.

Pre-clinical evidence suggests that 5-alpha reductase inhibitors (5ARi's), prescribed in the treatment of benign prostatic hyperplasia, reduce colorectal and gastro-oesophageal cancer incidence via action on the male hormonal pathway. However, few studies to date have investigated this association at the population level. Our study aimed to investigate the risk of colorectal and gastro-oesophageal cancers with the use of 5ARi's. We conducted a retrospective cohort study of new users of 5ARi's and alpha-blockers among patients with benign prostatic hyperplasia in the UK Clinical Practice Research Datalink. Patients were followed until a first ever diagnosis of colorectal or gastro-oesophageal cancer, death from any cause or end of registration with the general practice or 31st of December 2017. Cox proportional hazards models with inverse probability of treatment weights were used to calculate weighted hazard ratios (HR) and 95% confidence intervals (CIs) of incident colorectal cancer or gastro-oesophageal cancer associated with the use of 5ARi's compared to alpha-blockers. During a mean follow-up of 6.6 years, we found no association between the use of 5ARi's and colorectal (HR: 1.13, 95% CI 0.91-1.41) or gastro-oesophageal (HR 1.14, 95% CI 0.76-1.63) cancer risk compared to alpha-blockers. Sensitivity analysis showed largely consistent results when varying lag periods, using multiple imputations, and accounting for competing risk of death. Our study found no association between the use of 5ARi's and risk of colorectal or gastro-oesophageal cancer in men with benign prostatic hyperplasia.

Immunosuppression and cancer risk in kidney transplant recipients: A retrospective cohort study.

We assessed whether contemporary immunosuppression agents were associated with cancer among kidney transplant recipients (KTR), and if this association varied by age and sex. We studied a retrospective province-wide cohort of primary KTR (1997-2016). Employing multivariable Cox models, we estimated associations of cumulative doses of prednisone, mycophenolate and tacrolimus administered over the past 10 years, lagged by 2 years, with the incidence of primary malignant neoplasms (PMN). We assessed interactions with age and sex. To assess the impact of exposure recency, we used weighted cumulative exposure (WCE) modeling. Among 1064 KTR, 108 (10.2%) developed PMN over median follow-up of 73 months (interquartile range: 32-120). Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of 0.96 (0.64-1.43), 1.34 (0.96-1.86), and 1.06 (0.88-1.29) were estimated for cumulative daily doses of prednisone (5 mg), mycophenolate (1000 mg), and tacrolimus (2 mg) administered continuously over the past 10 years, respectively. PMN risk associated with cumulative tacrolimus exposure was modified by age (interaction p = .035) and was more pronounced in 15-year and 30-year-old KTR (aHRs of 1.57 [1.08-2.28] and 1.31 [1.03-1.66], respectively) in comparison to older KTR. PMN risk increase associated with higher cumulative mycophenolate dose was more pronounced in females (aHR = 1.86 [1.15-3.00]) than in males (aHR = 1.16 [0.74-1.81]; interaction p = .131). WCE analyses suggested increased PMN risk the higher the mycophenolate doses taken 5-10 years ago. A trend toward increased PMN risk with long-term mycophenolate exposure, particularly in females, and more pronounced risk with long-term tacrolimus exposure in younger KTR, identify opportunities for tailored immunosuppression to mitigate cancer risk.

Thiazide Diuretics and Risk of Colorectal Cancer: A Population-Based Cohort Study.

Evidence from clinical trials and observational studies on the association between thiazide diuretics and colorectal cancer risk is conflicting. We aimed to determine whether thiazide diuretics are associated with an increased colorectal cancer risk compared with dihydropyridine calcium channel blockers (dCCBs). A population-based, new-user cohort was assembled using the UK Clinical Practice Research Datalink. Between 1990-2018, we compared thiazide diuretic initiators with dCCB initiators and estimated hazard ratios (HR) with 95% confidence intervals (CIs) of colorectal cancer using Cox proportional hazard models. Models were weighted using standardized morbidity ratio weights generated from calendar time-specific propensity scores. The cohort included 377,760 thiazide diuretic initiators and 364,300 dCCB initiators, generating 3,619,883 person-years of follow-up. Compared with dCCBs, thiazide diuretics were not associated with colorectal cancer (weighted HR = 0.97, 95% CI: 0.90, 1.04). Secondary analyses yielded similar results, although an increased risk was observed among patients with inflammatory bowel disease (weighted HR = 2.45, 95% CI: 1.13, 5.35) and potentially polyps (weighted HR = 1.46, 95% CI: 0.93, 2.30). Compared with dCCBs, thiazide diuretics were not associated with an overall increased colorectal cancer risk. While these findings provide some reassurance, research is needed to corroborate the elevated risks observed among patients with inflammatory bowel disease and history of polyps.

Glucagon like peptide-1 receptor agonists and the risk of skin cancer among patients with type 2 diabetes: Population-based cohort study.

AIMS: The objective of this study was to determine whether the use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) is associated with an increased risk of melanoma and nonmelanoma skin cancer, separately, compared with the use of sulfonylureas among patients with type 2 diabetes. METHODS: Using the United Kingdom Clinical Practice Research Datalink (2007-2019), we assembled two new-user active comparator cohorts. In the first cohort assessing melanoma as the outcome, 11,786 new users of GLP-1 RAs were compared with 208,519 new users of sulfonylureas. In the second cohort assessing nonmelanoma skin cancer as the outcome, 11,774 new users of GLP-1 RAs were compared with 207,788 new users of sulfonylureas. Cox proportional hazards models weighted using propensity score fine stratification were fit to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of melanoma and nonmelanoma skin cancer, respectively. RESULTS: Compared with sulfonylureas, GLP-1 RAs were not associated with an increased risk of either melanoma (42.6 vs. 43.9 per 100,000 person-years, respectively; HR 0.96, 95% CI 0.53-1.75) or nonmelanoma skin cancer (243.9 vs. 229.9 per 100,000 person-years, respectively; HR 1.03, 95% CI 0.80-1.33). There was no evidence of an association between cumulative duration of use with either melanoma or nonmelanoma skin cancer. Consistent results were observed in secondary and sensitivity analyses. CONCLUSIONS: In this population-based cohort study, GLP-1 RAs were not associated with an increased risk of melanoma or nonmelanoma skin cancer, compared with sulfonylureas.

Sodium-glucose cotransporter-2 inhibitors and the risk of lung cancer among patients with type 2 diabetes.

We sought to determine whether the use of sodium-glucose cotransporter-2 (SGLT-2) inhibitors is associated with a decreased risk of incident lung cancers among patients with type 2 diabetes. We assembled a new-user, active comparator cohort of SGLT-2 inhibitor and dipeptidyl peptidase-4 (DPP-4) inhibitor users using the United Kingdom Clinical Practice Research Datalink. We fit Cox proportional hazards models with propensity score fine stratification weighting to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for incident lung cancer. Crude incidence rates were 0.94 per 1000 person-years among 69 675 SGLT-2 inhibitor users followed for a median of 2.4 years and 1.45 per 1000 person-years among 151 495 DPP-4 inhibitor users followed for a median of 3.7 years. No reduced short-term risk of lung cancer was observed among SGLT-2 inhibitor users after weighting (HR 0.96, 95% CI 0.77-1.21). Further research with a longer follow-up period may be warranted.

Clinically apparent Helicobacter pylori infection and the risk of incident Alzheimer's disease: A population-based nested case-control study.

INTRODUCTION: Our population-based study assessed whether clinically apparent Helicobacter pylori infection (CAHPI) is associated with the risk of Alzheimer's disease (AD). METHODS: We assembled a population-based cohort of all dementia-free subjects in the United Kingdom's Clinical Practice Research Datalink (UK CPRD), aged ≥50 years (1988-2017). Using a nested case-control approach, we matched each newly developed case of AD with 40 controls. Conditional logistic regression estimated odds ratios (ORs) with 95% confidence intervals (CIs) of AD associated with CAHPI compared with no CAHPI during ≥2 years before the index date. We also used salmonellosis as a negative control exposure. RESULTS: Among 4,262,092 dementia-free subjects, 40,455 developed AD after a mean 11 years of follow-up. CAHPI was associated with an increased risk of AD (OR, 1.11; 95% CI, 1.01-1.21) compared with no CAHPI. Salmonellosis was not associated with the risk of AD (OR, 1.03; 95% CI, 0.82-1.29). DISCUSSION: CAHPI was associated with a moderately increased risk of AD. HIGHLIGHTS: CAHPI was associated with an 11% increased risk of AD in subjects aged ≥50 years. The increase in the risk of AD reached a peak of 24% a decade after CAHPI onset. There was no major effect modification by age or sex. Sensitivity analyses addressing several potential biases led to consistent results.

Proton pump inhibitors and the risk of inflammatory bowel disease: population-based cohort study.

OBJECTIVE: To determine whether the use of proton pump inhibitors (PPIs) compared with the use of histamine-2 receptor antagonists (H2RAs) is associated with an increased risk of inflammatory bowel disease (IBD). DESIGN: Population-based cohort study designed to address the impact of protopathic bias. SETTING: General practices contributing data to the UK Clinical Practice Research Datalink GOLD. PARTICIPANTS: 1 498 416 initiators of PPIs and 322 474 initiators of H2RAs from 1 January 1990 to 31 December 2018, with follow-up until 31 December 2019. Patients were analysed according to the timing of the IBD diagnosis after treatment initiation (early vs late). MAIN OUTCOME MEASURES: Standardised morbidity ratio weighted Cox proportional hazards models were used to estimate marginal HRs and 95% CIs. In the early-event analysis, IBD diagnoses were assessed within the first 2 years of treatment initiation, an analysis subject to potential protopathic bias. In the late-event analysis, all exposures were lagged by 2 years to account for latency and minimise protopathic bias. RESULTS: In the early-event analysis, the use of PPIs was associated with an increased risk of IBD within the first 2 years of treatment initiation, compared with H2RAs (HR 1.39, 95% CI 1.14 to 1.69). In contrast, the use of PPIs was not associated with an increased risk of IBD in the late-event analysis (HR 1.05, 95% CI 0.90 to 1.22). The results remained consistent in several sensitivity analyses. CONCLUSIONS: Compared with H2RAs, PPIs were not associated with an increased risk of IBD, after accounting for protopathic bias.

Contemporary trends in the utilization of second-line pharmacological therapies for type 2 diabetes in the United States and the United Kingdom.

AIM: To examine trends of second-line glucose-lowering therapies among patients with type 2 diabetes (T2D) initiating first-line metformin in the United States and the United Kingdom, overall and by subgroups of cardiovascular disease (CVD) and calendar time. METHODS: Using the US Optum Clinformatics and the UK Clinical Practice Research Datalink, we identified adults with T2D who initiated first-line metformin or sulphonylurea monotherapy, separately, from 2013 to 2019. Within both cohorts, we identified patterns of second-line medications through June 2021. We stratified patterns by CVD and calendar time to investigate the impact of rapidly evolving treatment guidelines. RESULTS: We identified 148 511 and 169 316 patients initiating treatment with metformin monotherapy in the United States and the United Kingdom, respectively. Throughout the study period, sulphonylureas and dipeptidyl peptidase-4 inhibitors were the most frequently initiated second-line medications in the United States (43.4% and 18.2%, respectively) and the United Kingdom (42.5% and 35.8%, respectively). After 2018, sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide-1 receptor agonists were more commonly used as second-line agents in the United States and the United Kingdom, although these agents were not preferentially prescribed among patients with CVD. Initiation of first-line sulphonylureas was much less common, and most sulphonylurea initiators had metformin added as the second-line agent. CONCLUSIONS: This international cohort study shows that sulphonylureas remain the most common second-line medications prescribed following metformin in both the United States and the United Kingdom. Despite recommendations, the use of newer glucose-lowering therapies with cardiovascular benefits remains low.

Hydrochlorothiazide use and risk of keratinocyte carcinoma and melanoma: A multisite population-based cohort study.

BACKGROUND: The association between hydrochlorothiazide (HCTZ) and skin cancer remains controversial. OBJECTIVE: To determine whether HCTZ is associated with an increased risk of skin cancer compared with angiotensin-converting enzyme inhibitors and calcium channel blockers. METHODS: Two new-user, active comparator cohorts were assembled using 6 Canadian databases. Site-specific hazard ratios (HRs) with 95% CIs were estimated using standardized morbidity ratio weighted Cox proportional hazard models and pooled using random-effects meta-analysis. RESULTS: HCTZ was not associated with an overall increased risk of keratinocyte carcinoma compared with angiotensin-converting enzyme inhibitors or calcium channel blockers, although increased risks were observed with longer durations (≥10 years; HR: 1.12; 95% CI: 1.03-1.21) and higher cumulative doses (≥100,000 mg; HR: 1.49; 95% CI: 1.27-1.76). For melanoma, there was no association with angiotensin-converting enzyme inhibitors, but a 32% increased risk with calcium channel blockers (crude incidence rates: 64.2 vs 58.4 per 100,000 person-years; HR: 1.32; 95% CI: 1.19-1.46; estimated number needed to harm at 5 years of follow-up: 1627 patients), with increased risks with longer durations and cumulative doses. LIMITATIONS: Residual confounding due to the observational design. CONCLUSIONS: Increased risks of keratinocyte carcinoma and melanoma were observed with longer durations of use and higher cumulative doses of HCTZ.

Proton pump inhibitors and risk of gastric cancer: population-based cohort study.

OBJECTIVE: To determine whether new users of proton pump inhibitors (PPIs) are at an increased risk of gastric cancer compared with new users of histamine-2 receptor antagonists (H2RAs). DESIGN: Using the UK Clinical Practice Research Datalink, we conducted a population-based cohort study using a new-user active comparator design. From 1 January 1990 to 30 April 2018, we identified 973 281 new users of PPIs and 193 306 new users of H2RAs. Cox proportional hazards models were fit to estimate HRs and 95% CIs of gastric cancer, and the number needed to harm was estimated using the Kaplan-Meier method. The models were weighted using standardised mortality ratio weights using calendar time-specific propensity scores. Secondary analyses assessed duration and dose-response associations. RESULTS: After a median follow-up of 5.0 years, the use of PPIs was associated with a 45% increased risk of gastric cancer compared with the use of H2RAs (HR 1.45, 95% CI 1.06 to 1.98). The number needed to harm was 2121 and 1191 for five and 10 years after treatment initiation, respectively. The HRs increased with cumulative duration, cumulative omeprazole equivalents and time since treatment initiation. The results were consistent across several sensitivity analyses. CONCLUSION: The findings of this large population-based cohort study indicate that the use of PPIs is associated with an increased risk of gastric cancer compared with the use of H2RAs, although the absolute risk remains low.

Proton pump inhibitors and risk of colorectal cancer.

OBJECTIVE: To determine whether proton pump inhibitors (PPIs) are associated with an increased risk of colorectal cancer, compared with histamine-2 receptor antagonists (H2RAs). DESIGN: The United Kingdom Clinical Practice Research Datalink was used to identify initiators of PPIs and H2RA from 1990 to 2018, with follow-up until 2019. Cox proportional hazards models were fit to estimate marginal HRs and 95% CIs of colorectal cancer. The models were weighted using standardised mortality ratio weights using calendar time-specific propensity scores. Prespecified secondary analyses assessed associations with cumulative duration, cumulative dose and time since treatment initiation. The number needed to harm was calculated at five and 10 years of follow-up. RESULTS: The cohort included 1 293 749 and 292 387 initiators of PPIs and H2RAs, respectively, followed for a median duration of 4.9 years. While the use of PPIs was not associated with an overall increased risk of colorectal cancer (HR: 1.02, 95% CI 0.92 to 1.14), HRs increased with cumulative duration of PPI use (<2 years, HR: 0.93, 95% CI 0.83 to 1.04; 2-4 years, HR: 1.45, 95% CI 1.28 to 1.60; ≥4 years, HR: 1.60, 95% CI 1.42 to 1.80). Similar patterns were observed with cumulative dose and time since treatment initiation. The number needed to harm was 5343 and 792 for five and 10 years of follow-up, respectively. CONCLUSION: While any use of PPIs was not associated with an increased risk of colorectal cancer compared with H2RAs, prolonged use may be associated with a modest increased risk of this malignancy.

Glucagon-Like Peptide 1 Receptor Agonists and Risk of Anaphylactic Reaction Among Patients With Type 2 Diabetes: A Multisite Population-Based Cohort Study.

Case reports and a pharmacovigilance analysis have linked glucagon-like peptide 1 receptor agonists (GLP-1 RAs) with anaphylactic reactions, but real-world evidence for this possible association is lacking. Using databases from the United Kingdom (Clinical Practice Research Datalink) and the United States (Medicare, Optum (Optum, Inc., Eden Prairie, Minnesota), and IBM MarketScan (IBM, Armonk, New York)), we employed a new-user, active comparator study design wherein initiators of GLP-1 RAs were compared with 2 different active comparator groups (initiators of dipeptidyl peptidase 4 (DPP-4) inhibitors and initiators of sodium-glucose cotransporter 2 (SGLT-2) inhibitors) between 2007 and 2019. Propensity score fine stratification weighted Cox proportional hazards models were fitted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for an anaphylactic reaction. Database-specific HRs were pooled using random-effects models. Compared with the use of DPP-4 inhibitors (n = 1,641,520), use of GLP-1 RAs (n = 324,098) generated a modest increase in the HR for anaphylactic reaction, with a wide 95% CI (36.9 per 100,000 person-years vs. 32.1 per 100,000 person-years, respectively; HR = 1.15, 95% CI: 0.94, 1.42). Compared with SGLT-2 inhibitors (n = 366,067), GLP-1 RAs (n = 259,929) were associated with a 38% increased risk of anaphylactic reaction (40.7 per 100,000 person-years vs. 29.4 per 100,000 person-years, respectively; HR = 1.38, 95% CI: 1.02, 1.87). In this large, multisite population-based cohort study, GLP-1 RAs were associated with a modestly increased risk of anaphylactic reaction when compared with DPP-4 inhibitors and SGLT-2 inhibitors.

Aromatase inhibitors and the incidence of Parkinson disease: A population-based cohort study.

BACKGROUND: Current guidelines recommend the treatment of hormone receptor-positive breast cancer with aromatase inhibitors (AIs) and tamoxifen in the adjuvant setting. Some observational studies have raised concerns that tamoxifen may be associated with an increased risk of Parkinson disease (PD). However, no studies have directly compared the risk of PD between AIs and tamoxifen in women diagnosed with breast cancer. METHODS: Using the UK Clinical Practice Research Datalink, the authors assembled a cohort of women newly diagnosed with breast cancer and newly treated with either AIs or tamoxifen between January 1, 1995, and December 31, 2017. Patients were followed 1 year after treatment initiation (ie, a 1-year lag) until an incident diagnosis of PD or were censored at death from any cause, the date of transfer out of the practice, or the end of the study period (December 31, 2018). Cox proportional hazards models with inverse probability of treatment weights were used to estimate weighted hazard ratios (HRs) and 95% confidence intervals (CIs) for PD comparing AIs with tamoxifen and accounting for more than 30 confounders. RESULTS: In all, 30,140 women with nonmetastatic breast cancer were identified: 13,838 initiated AIs, and 16,302 initiated tamoxifen. Compared with tamoxifen, AIs were not associated with an increased risk of PD (HR, 0.94; 95% CI, 0.60-1.47). Consistent results were observed across all secondary and sensitivity analyses. CONCLUSIONS: In this large observational study, the use of AIs, in comparison with tamoxifen, was not associated with an increased risk of PD in women diagnosed with nonmetastatic breast cancer in a real-world setting. LAY SUMMARY: Previous studies have indicated that tamoxifen may increase the risk of Parkinson disease in the treatment of breast cancer. However, no studies have directly compared the risk of Parkinson disease between aromatase inhibitors and tamoxifen. This study included 30,140 women diagnosed with breast cancer and treated with aromatase inhibitors or tamoxifen. Overall, compared with tamoxifen, aromatase inhibitors were not associated with an increased risk of Parkinson disease in women diagnosed with breast cancer. This study provides an important addition to the comparative safety profile of aromatase inhibitors and tamoxifen in the treatment of breast cancer.

Rationale, Strengths, and Limitations of Real-World Evidence in Oncology: A Canadian Review and Perspective.

Randomized controlled trials (RCTs) continue to be the basis for essential evidence regarding the efficacy of interventions such as cancer therapies. Limitations associated with RCT designs, including selective study populations, strict treatment regimens, and being time-limited, mean they do not provide complete information about an intervention's safety or the applicability of the trial's results to a wider range of patients seen in real-world clinical practice. For example, recent data from Alberta showed that almost 40% of patients in the province's cancer registry would be trial-ineligible per common exclusion criteria. Real-world evidence (RWE) offers an opportunity to complement the RCT evidence base with this kind of information about safety and about use in wider patient populations. It is also increasingly recognized for being able to provide information about an intervention's effectiveness and is considered by regulators as an important component of the evidence base in drug approvals. Here, we examine the limitations of RCTs in oncology research, review the different types of RWE available in this area, and discuss the strengths and limitations of RWE for complementing RCT oncology data.

Incretin-Based Drugs and the Incidence of Prostate Cancer Among Patients With Type 2 Diabetes.

BACKGROUND: There is some evidence that glucagon-like peptide 1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors have chemopreventive effects on prostate cancer cells but real-world evidence for this possible effect is lacking. Thus, the objective of this study was to estimate whether use of GLP-1 receptor agonists and DPP-4 inhibitors, separately, is associated with a decreased risk of prostate cancer among patients with type 2 diabetes. METHODS: We assembled two new-user, active-comparator cohorts using the UK Clinical Practice Research Datalink (2007 to 2019). The first cohort included 5,063 initiators of GLP-1 receptor agonists and 112,955 of sulfonylureas. The second cohort included 53,529 initiators of DPP-4 inhibitors and 114,417 of sulfonylureas. We fit Cox proportional hazards models to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for prostate cancer. We weighted the models using propensity score fine stratification, which considered over 50 potential confounders. RESULTS: GLP-1 receptor agonists were associated with a decreased risk of prostate cancer when compared with sulfonylureas (incidence rates = 156.4 vs. 232.0 per 100,000 person-years, respectively; HR = 0.65; 95% CI = 0.43, 0.99). DPP-4 inhibitors were also associated with a decreased risk of prostate cancer when compared with sulfonylureas (incidence rates = 316.2 vs. 350.5 events per 100,000 person-years, respectively; HR = 0.90; 95% CI = 0.81, 1.00). CONCLUSIONS: The results of this study are consistent with the hypothesis that the use of GLP-1 receptor agonists and DPP-4 inhibitors, separately, may decrease the risk of prostate cancer when compared with the use of sulfonylureas.

Tramadol versus codeine and the short-term risk of cardiovascular events in patients with non-cancer pain: A population-based cohort study.

AIMS: The effect of tramadol on the cardiovascular system is largely unknown. There is concern that, with its multimodal mechanism of action to increase serotonin and norepinephrine levels in the body, it could increase the risk of arterial ischaemia and cardiovascular events. We aimed to compare the short-term risk of cardiovascular events with the use of tramadol to that of codeine among patients with non-cancer pain. METHODS: We conducted a retrospective population-based cohort study using data from the Clinical Practice Research Datalink (CPRD) with new users of tramadol or codeine from April 1998 to March 2017. Exposure was defined using an approach analogous to an intention-to-treat, with a maximum follow-up of 30 days. The primary endpoint was myocardial infarction, and secondary endpoints were unstable angina, ischaemic stroke, coronary revascularization, cardiovascular death and all-cause mortality. Hazard ratios (HRs) were estimated using Cox proportional hazards models, adjusted for high-dimensional propensity score. RESULTS: The final cohort included 123 394 tramadol users and 914 333 codeine users. When tramadol was compared to codeine, the adjusted hazard ratio (HR) of myocardial infarction was 1.00 (95% CI 0.81-1.24). There was also no evidence of elevated risks of unstable angina (0.92; 95% CI 0.67-1.27), ischaemic stroke (0.98; 95% CI 0.82-1.17), coronary revascularization (0.97; 95% CI 0.69-1.38), cardiovascular death (1.07; 95% CI 0.93-1.23) or all-cause mortality (1.03; 95% CI 0.94-1.14) when tramadol was compared to codeine. CONCLUSIONS: Short-term use of tramadol, compared with codeine, was not associated with an increased risk of cardiac events among patients with non-cancer pain.

Angiotensin-converting enzyme inhibitors and risk of age-related macular degeneration in individuals with hypertension.

AIMS: Several observational studies have examined the potential protective effect of angiotensin-converting enzyme inhibitor (ACE-I) use on the risk of age-related macular degeneration (AMD) and have reported contradictory results owing to confounding and time-related biases. We aimed to assess the risk of AMD in a base cohort of patients aged 40 years and above with hypertension among new users of ACE-I compared to an active comparator cohort of new users of calcium channel blockers (CCB) using data obtained from IQVIA Medical Research Data, a primary care database in the UK. METHODS: In this study, 53 832 and 43 106 new users of ACE-I and CCB were included between 1995 and 2019, respectively. In an on-treatment analysis, patients were followed up from the time of index drug initiation to the date of AMD diagnosis, loss to follow-up, discontinuation or switch to the comparator drug. A comprehensive range of covariates were used to estimate propensity scores to weight and match new users of ACE-I and CCB. Standardized mortality ratio weighted Cox proportional hazards model was used to estimate hazard ratios of developing AMD. RESULTS: During a median follow-up of 2 years (interquartile range 1-5 years), the incidence rate of AMD was 2.4 (95% confidence interval 2.2-2.6) and 2.2 (2.0-2.4) per 1000 person-years among the weighted new users of ACE-I and CCB, respectively. There was no association of ACE-I use on the risk of AMD compared to CCB use in either the propensity score weighted or matched, on-treatment analysis (adjusted hazard ratio: 1.07 [95% confidence interval 0.90-1.27] and 0.87 [0.71-1.07], respectively). CONCLUSION: We found no evidence that the use of ACE-I is associated with risk of AMD in patients with hypertension.

A systematic, concept-based method of developing the exposure measure for drug safety and effectiveness studies.

PURPOSE: In drug safety and effectiveness studies based on secondary data, the choice of an appropriate exposure measure for a given outcome can be challenging. Different measures of exposure can yield different estimates of treatment effect and safety. There is a knowledge gap with respect to developing and refining measures of drug exposure, to ensure that the exposure measure addresses the study question and is suitable for statistical analysis. METHODS: We present a transparent, step-by-step approach to the development of drug exposure measures involving secondary data. This approach would be of interest to students and investigators with initial training in pharmacoepidemiology. We illustrate the approach using a study about Parkinson's disease. RESULTS: We described the exposure specifications according to the study question. Next, we refined the exposure measure by linking it to knowledge about four major concepts in drug safety and effectiveness studies: drug use patterns, duration, timing, and dose. We then used this knowledge to guide the ultimate choice of exposure measure: time-varying, cumulative 6-month exposure to tamsulosin (a drug used to treat prostate hyperplasia). CONCLUSIONS: The proposed approach links exposure specifications to four major concepts in drug safety and effectiveness studies. Formulating subject-matter knowledge about these major concepts provides an avenue to develop the rationale and specifications for the exposure measure.

Aromatase Inhibitors and the Risk of Cardiovascular Outcomes in Women With Breast Cancer: A Population-Based Cohort Study.

BACKGROUND: The association between aromatase inhibitors and cardiovascular outcomes among women with breast cancer is controversial. Given the discrepant findings from randomized controlled trials and observational studies, additional studies are needed to address this safety concern. METHODS: We conducted a population-based cohort study using the UK Clinical Practice Research Datalink linked to the Hospital Episode Statistics and Office for National Statistics databases. The study population consisted of women newly diagnosed with breast cancer initiating hormonal therapy with aromatase inhibitors or tamoxifen between April 1, 1998, and February 29, 2016. We usedCox proportional hazards models with inverse probability of treatment and censoring weighting to estimate hazard ratios (HRs) with 95% CIs comparing new users of aromatase inhibitors with new users of tamoxifen for each of the study outcomes (myocardial infarction, ischemic stroke, heart failure, and cardiovascular mortality). RESULTS: The study population consisted of 23 525 patients newly diagnosed with breast cancer, of whom 17 922 initiated treatment with either an aromatase inhibitor or tamoxifen (8139 and 9783, respectively). The use of aromatase inhibitors was associated with a significantly increased risk of heart failure (incidence rate, 5.4 versus 1.8 per 1000 person-years; HR, 1.86 [95% CI, 1.14-3.03]) and cardiovascular mortality (incidence rate, 9.5 versus 4.7 per 1000 person-years; HR, 1.50 [95% CI, 1.11-2.04]) compared with the use of tamoxifen. Aromatase inhibitors were associated with elevated HRs, but with CIs including the null value, for myocardial infarction (incidence rate, 3.9 versus 1.8 per 1000 person-years; HR, 1.37 [95% CI, 0.88-2.13]) and ischemic stroke (incidence rate, 5.6 versus 3.2 per 1000 person-years; HR, 1.19 [95% CI, 0.82-1.72]). CONCLUSIONS: In this population-based study, aromatase inhibitors were associated with increased risks of heart failure and cardiovascular mortality compared with tamoxifen. There were also trends toward increased risks, although nonsignificant, of myocardial infarction and ischemic stroke. The increased risk of cardiovascular events associated with aromatase inhibitors should be balanced with their favorable clinical benefits compared with tamoxifen.

Biases in Evaluating the Safety and Effectiveness of Drugs for the Treatment of COVID-19: Designing Real-World Evidence Studies.

The coronavirus disease 2019 pandemic, which was caused by the severe acute respiratory syndrome coronavirus 2, has led to an unprecedented effort to generate real-world evidence on the safety and effectiveness of various treatments. A growing number of observational studies in which the effects of certain drugs were evaluated have been conducted, including several in which researchers assessed whether hydroxychloroquine improved outcomes in infected individuals and whether renin-angiotensin-aldosterone system inhibitors have detrimental effects. In the present article, we review and illustrate how immortal time bias and selection bias were present in several of these studies. Understanding these biases and how they can be avoided may prove important for future observational studies assessing the effectiveness and safety of potentially promising drugs during the coronavirus 19 pandemic.