Lesley Wise

Oral bisphosphonates and risk of cancer of oesophagus, stomach, and colorectum: case-control analysis within a UK primary care cohort

Objective To examine the hypothesis that risk of oesophageal, but not of gastric or colorectal, cancer is increased in users of oral bisphosphonates. Design Nested case-control analysis within a primary care cohort of about 6 million people in the UK, with prospectively recorded information on prescribing of bisphosphonates. Setting UK General Practice Research Database cohort. Participants Men and women aged 40 years or over—2954 with oesophageal cancer, 2018 with gastric cancer, and 10 641 with colorectal cancer, diagnosed in 1995-2005; five controls per case matched for age, sex, general practice, and observation time. Main outcome measures Relative risks for incident invasive cancers of the oesophagus, stomach, and colorectum, adjusted for smoking, alcohol, and body mass index. Results The incidence of oesophageal cancer was increased in people with one or more previous prescriptions for oral bisphosphonates compared with those with no such prescriptions (relative risk 1.30, 95% confidence interval 1.02 to1.66; P=0.02). Risk of oesophageal cancer was significantly higher for 10 or more prescriptions (1.93, 1.37 to 2.70) than for one to nine prescriptions (0.93, 0.66 to 1.31) (P for heterogeneity=0.002), and for use for over 3 years (on average, about 5 years: relative risk v no prescription, 2.24, 1.47 to 3.43). Risk of oesophageal cancer did not differ significantly by bisphosphonate type, and risk in those with 10 or more bisphosphonate prescriptions did not vary by age, sex, smoking, alcohol intake, or body mass index; by diagnosis of osteoporosis, fracture, or upper gastrointestinal disease; or by prescription of acid suppressants, non-steroidal anti-inflammatory drugs, or corticosteroids. Cancers of the stomach and colorectum were not associated with prescription of bisphosphonate: relative risks for one or more versus no prescriptions were 0.87 (0.64 to 1.19) and 0.87 (0.77 to 1.00). The specificity of the association for oesophageal cancer argues against methodological problems in the selection of cases and controls or in the analysis. Conclusions The risk of oesophageal cancer increased with 10 or more prescriptions for oral bisphosphonates and with prescriptions over about a five year period. In Europe and North America, the incidence of oesophageal cancer at age 60-79 is typically 1 per 1000 population over five years, and this is estimated to increase to about 2 per 1000 with five years’ use of oral bisphosphonates.

Antidepressant treatment and the risk of fatal and non-fatal self harm in first episode depression: nested case-control study

Abstract Objective To compare the risk of non-fatal self harm and suicide in patients taking selective serotonin reuptake inhibitors (SSRIs) with that of patients taking tricyclic antidepressants, as well as between different SSRIs and different tricyclic antidepressants. Design Nested case-control study. Setting Primary care in the United Kingdom. Participants 146 095 individuals with a first prescription of an antidepressant for depression. Main outcome measures Suicide and non-fatal self harm. Results 1968 cases of non-fatal self harm and 69 suicides occurred. The overall adjusted odds ratio of non-fatal self harm was 0.99 (95% confidence interval 0.86 to 1.14) and that of suicide 0.57 (0.26 to 1.25) in people prescribed SSRIs compared with those prescribed tricyclic antidepressants. We found little evidence that associations differed over time since starting or stopping treatment. We found some evidence that risks of non-fatal self harm in people prescribed SSRIs compared with those prescribed tricyclic antidepressants differed by age group (interaction P = 0.02). The adjusted odds ratio of non-fatal self harm for people prescribed SSRIs compared with users of tricylic antidepressants for those aged 18 or younger was 1.59 (1.01 to 2.50), but no association was apparent in other age groups. No suicides occurred in those aged 18 or younger currently or recently prescribed tricyclic antidepressants or SSRIs. Conclusion We found no evidence that the risk of suicide or non-fatal self harm in adults prescribed SSRIs was greater than in those prescribed tricyclic antidepressants. We found some weak evidence of an increased risk of non-fatal self harm for current SSRI use among those aged 18 or younger. However, preferential prescribing of SSRIs to patients at higher risk of suicidal behaviour cannot be ruled out.

Varenicline and suicidal behaviour: a cohort study based on data from the General Practice Research Database

Objective To determine whether varenicline, a recently licensed smoking cessation product, is associated with an increased risk of suicide and suicidal behaviour compared with alternative treatments bupropion and nicotine replacement therapy. Design Cohort study nested within the General Practice Research Database. Setting Primary care in the United Kingdom. Participants 80 660 men and women aged 18-95 years were prescribed a new course of a smoking cessation product between 1 September 2006 and 31 May 2008; the initial drugs prescribed during follow-up were nicotine replacement products (n=63 265), varenicline (n=10 973), and bupropion (n=6422). Main outcome measures Primary outcomes were fatal and non-fatal self harm, secondary outcomes were suicidal thoughts and depression, all investigated with Cox’s proportional hazards models. Results There was no clear evidence that varenicline was associated with an increased risk of fatal (n=2) or non-fatal (n=166) self harm, although a twofold increased risk cannot be ruled out on the basis of the upper limit of the 95% confidence interval. Compared with nicotine replacement products, the hazard ratio for self harm among people prescribed varenicline was 1.12 (95% CI 0.67 to 1.88), and it was 1.17 (0.59 to 2.32) for people prescribed bupropion. There was no evidence that varenicline was associated with an increased risk of depression (n=2244) (hazard ratio 0.88 (0.77 to1.00)) or suicidal thoughts (n=37) (1.43 (0.53 to 3.85)). Conclusion Although a twofold increased risk of self harm with varenicline cannot be ruled out, these findings provide some reassurance concerning its association with suicidal behaviour.

Investigation of the Temporal Association of Guillain-Barré Syndrome With Influenza Vaccine and Influenzalike Illness Using the United Kingdom General Practice Research Database

In 1976, the national swine influenza vaccination program in the United States was suspended because of an increased risk of Guillain-Barré syndrome. Subsequent studies of seasonal influenza vaccine have given conflicting results. The authors used the self-controlled case series method to investigate the relation of Guillain-Barré syndrome with influenza vaccine and influenzalike illness using cases recorded in the General Practice Research Database from 1990 to 2005 in the United Kingdom. The relative incidence of Guillain-Barré syndrome within 90 days of vaccination was 0.76 (95% confidence interval: 0.41, 1.40). In contrast, the relative incidence of Guillain-Barré syndrome within 90 days of an influenzalike illness was 7.35 (95% confidence interval: 4.36, 12.38), with the greatest relative incidence (16.64, 95% confidence interval: 9.37, 29.54) within 30 days. The relative incidence was similar (0.89, 95% confidence interval: 0.42, 1.89) when the analysis was restricted to a subset of validated cases. The authors found no evidence of an increased risk of Guillain-Barré syndrome after seasonal influenza vaccine. The finding of a greatly increased risk after influenzalike illness is consistent with anecdotal reports of a preceding respiratory illness in Guillain-Barré syndrome and has important implications for the risk/benefit assessment that would be carried out should pandemic vaccines be deployed in the future.

New approaches to drug safety: a pharmacovigilance tool kit

The importance of pharmacovigilance — the ongoing assessment of the safety of a marketed medicine — has been increasingly appreciated in recent years, owing in part to high-profile safety issues with widely used drugs. In response, strategies to improve the collection, integration and analysis of data related to post-marketing drug safety are being initiated or enhanced. In this article, we summarize the key tools that are available for pharmacovigilance, discuss which might be the most appropriate to use in different situations and consider the future directions of the field.

Menopausal hormone therapy and risk of gastrointestinal cancer: nested case-control study within a prospective cohort, and meta-analysis.

Use of menopausal hormone therapy (HT) has been associated with reduced risk of colorectal cancer; evidence for its effect on other gastrointestinal cancers is limited. We conducted a nested case–control study within a UK cohort, and meta‐analyses combining our results with those from published studies. Our study included women aged 50+ in the UK General Practice Research Database (GPRD): 1,054 with oesophageal, 750 with gastric and 4,708 with colorectal cancer, and 5 age‐ and practice‐matched controls per case. Relative risks (RRs) and 95% confidence intervals (CIs) for cancer in relation to prospectively‐recorded HT prescriptions were estimated by conditional logistic regression. Women prescribed HT had a reduced risk of oesophageal cancer (adjusted RR for 1+ vs. no HT prescriptions, 0.68, 95% CI 0.53–0.88; p = 0.004), gastric cancer (0.75, 0.54–1.05; p = 0.1) and colorectal cancer (0.81, 0.73–0.90; p < 0.001). There were no significant differences in cancer risk by HT type, estimated duration of HT use or between past and current users. In meta‐analyses, risks for ever vs. never use of HT were significantly reduced for all three cancers (summary RR for oesophageal cancer, 0.68, 0.55–0.84, p < 0.001; for gastric cancer, 0.78, 0.65–0.94, p = 0.008; for colorectal cancer, 0.84, 0.81–0.88, p < 0.001). In high‐income countries, estimated incidence over 5 years of these three cancers combined in women aged 50–64 was 2.9/1,000 in HT users and 3.6/1,000 in never users. The absolute reduction in risk of these cancers in HT users is small compared to the HT‐associated increased risk of breast cancer.

Bell’s Palsy and Parenteral Inactivated Influenza Vaccine

Concern about a possible increased risk of Bell’s palsy after parenteral inactivated influenza vaccine was raised following the publication in 2004 of a Swiss study in which there was an increased risk following the nasal inactivated formulation of the vaccine. When data from passive reporting systems in the United States and the United Kingdom were examined there was some evidence of increased reporting following the parenteral vaccine. A large population based study using the General Practice Research Database (GPRD) was therefore performed to test the hypothesis that there was an increased risk of Bell’s palsy in the three months following parenteral inactivated influenza vaccine. The risk was also assessed for the same period following pneumococcal vaccine and was stratified into three age groups (

European perspective on risk management and drug safety.

Risk management is an approach that has been used for many years in areas of business and government such as finance and insurance, but its use in the regulation of medicines has until recently been limited to tools such as the prescription status of a medicine (prescription‐only or over‐the‐counter), the information provided to health‐care professionals and patients, and the collection and evaluation of postmarketing safety reports.

Post-licensure comparison of the safety profile of diphtheria/tetanus/whole cell pertussis/haemophilus influenza type b vaccine and a 5-in-1 diphtheria/tetanus/acellular pertussis/haemophilus influenza type b/polio vaccine in the United Kingdom.

General practitioner consultation data were used to compare the reactogenicity in infants of a 5-in-1 acellular pertussis vaccine (DTaP(5)/Hib/IPV) introduced in the United Kingdom in 2004 to the 4-in-1 whole cell-pertussis vaccine (DTwP/Hib) that it replaced. For each vaccine the incidence in the week following vaccination was compared to other periods to obtain a relative incidence. A lower relative incidence of crying, fever and local reactions was seen with DTaP(5)/Hib/IPV than DTwP/Hib. Although there were no other significant differences between vaccines the relative incidence was significantly above one on the day of vaccination for convulsions following DTwP/Hib and for apnoea/collapse following DTaP(5)/Hib/IPV.

Benefit-risk assessment in a post-market setting: a case study integrating real-life experience into benefit-risk methodology.

Difficulties may be encountered when undertaking a benefit–risk assessment for an older product with well‐established use but with a benefit–risk balance that may have changed over time. This case study investigates this specific situation by applying a formal benefit–risk framework to assess the benefit–risk balance of warfarin for primary prevention of patients with atrial fibrillation.