Validity of Routine Health Data To Identify Safety Outcomes of Interest For Covid-19 Vaccines and Therapeutics in the Context of the Emerging Pandemic: A Comprehensive Literature Review

Introduction

Regulatory guidance encourages transparent reporting of information on the quality and validity of electronic health record data being used to generate real-world benefit-risk evidence for vaccines and therapeutics. We aimed to provide an overview of the availability of validated diagnostic algorithms for selected safety endpoints for Coronavirus disease 2019 (COVID-19) vaccines and therapeutics in the context of the emerging pandemic prior to December 2020.

Methods

We reviewed the literature up to December 2020 to identify validation studies for various safety events of interest, including myocardial infarction, arrhythmia, myocarditis, acute cardiac injury, vasculitis/vasculopathy, venous thromboembolism, stroke, respiratory distress syndrome (RDS), pneumonitis, cytokine release syndrome (CRS), multiple organ dysfunction syndrome, and renal failure. We included studies published between 2015 and 2020 that were considered high quality assessed with QUADAS and that reported positive predictive values (PPVs).

Results

Out of 43 identified studies, we found that diagnostic algorithms for cardiovascular outcomes were supported by the highest number of validation studies (n=17). Accurate algorithms are available for myocardial infarction (median PPV 80%; IQR 22%), arrhythmia (PPV range >70%), venous thromboembolism (median PPV: 73%) and ischaemic stroke (PPV range ≥85%). We found a lack of validation studies for less common respiratory and cardiac safety outcomes of interest (eg, pneumonitis and myocarditis), as well as for COVID-specific complications (CRS, RDS).

Conclusion

There is a need for better understanding of barriers to conducting validation studies, including data governance restrictions. Regulatory guidance should promote embedding validation within real-world EHR research used for decision-making.

Totality of evidence of the effectiveness of repurposed therapies for COVID-19: Can we use real-world studies alongside randomized controlled trials?

Rapid and robust strategies to evaluate the efficacy and effectiveness of novel and existing pharmacotherapeutic interventions (repurposed treatments) in future pandemics are required. Observational "real-world studies" (RWS) can report more quickly than randomized controlled trials (RCTs) and would have value were they to yield reliable results. Both RCTs and RWS were deployed during the coronavirus disease 2019 (COVID-19) pandemic. Comparing results between them offers a unique opportunity to determine the potential value and contribution of each. A learning review of these parallel evidence channels in COVID-19, based on quantitative modeling, can help improve speed and reliability in the evaluation of repurposed therapeutics in a future pandemic. Analysis of all-cause mortality data from 249 observational RWS and RCTs across eight treatment regimens for COVID-19 showed that RWS yield more heterogeneous results, and generally overestimate the effect size subsequently seen in RCTs. This is explained in part by a few study factors: the presence of RWS that are imbalanced for age, gender, and disease severity, and those reporting mortality at 2 weeks or less. Smaller studies of either type contributed negligibly. Analysis of evidence generated sequentially during the pandemic indicated that larger RCTs drive our ability to make conclusive decisions regarding clinical benefit of each treatment, with limited inference drawn from RWS. These results suggest that when evaluating therapies in future pandemics, (1) large RCTs, especially platform studies, be deployed early; (2) any RWS should be large and should have adequate matching of known confounders and long follow-up; (3) reporting standards and data standards for primary endpoints, explanatory factors, and key subgroups should be improved; in addition, (4) appropriate incentives should be in place to enable access to patient-level data; and (5) an overall aggregate view of all available results should be available at any given time.

Real world safety of methoxyflurane analgesia in the emergency setting: a comparative hybrid prospective-retrospective post-authorisation safety study

BACKGROUND

Low-dose analgesic methoxyflurane (Penthrox®) was approved in Europe for emergency relief of moderate to severe pain in conscious adults with trauma in 2015. A comparative post-authorisation safety study (PASS) was conducted to assess the risk of hepatotoxicity and nephrotoxicity with methoxyflurane during routine clinical practice.

METHODS

This was a comparative hybrid prospective-retrospective cohort study. The comparative cohorts consisted of adults who were given methoxyflurane (methoxyflurane cohort) or another analgesic (concurrent cohort) routinely used for moderate to severe trauma and associated pain in the emergency setting (ambulance and Emergency Department) in the UK between December 2016 and November 2018. Hepatic and renal events were captured in the ensuing 12 weeks. A blinded clinical adjudication committee assessed events. A historical comparator cohort (non-concurrent cohort) was identified from patients with fractures in the English Hospital Episode Statistics (HES) accident and emergency database from November 2013 and November 2015 (before commercial launch of methoxyflurane). Hepatic and renal events were captured in the ensuing 12 weeks via linkage with the Clinical Practice Research Datalink (CPRD) and HES hospital admissions databases.

RESULTS

Overall, 1,236, 1,101 and 45,112 patients were analysed in the methoxyflurane, concurrent and non-concurrent comparator cohorts respectively. There was no significant difference in hepatic events between the methoxyflurane and concurrent cohorts (1.9% vs. 3.0%, P = 0.079) or between the methoxyflurane and non-concurrent cohorts (1.9% vs. 2.5%, P = 0.192). Renal events were significantly less common in the methoxyflurane cohort than in the concurrent cohort (2.3% vs. 5.6%, P < 0.001). For methoxyflurane versus non-concurrent cohort the lower occurrence of renal events (2.3% vs. 3.2%, P = 0.070) was not statistically significant. Multivariable adjustment did not change these associations.

CONCLUSIONS

Methoxyflurane administration was not associated with an increased risk of hepatotoxicity or nephrotoxicity compared with other routinely administered analgesics and was associated with a reduced risk of nephrotoxicity compared with other routinely administered analgesics.

TRIAL REGISTRATION

Study registered in the EU PAS Register (ENCEPP/SDPP/13040).

Malignancy rates in Crohn's disease patients with perianal fistula: A German retrospective cohort study

BACKGROUND

Patients with inflammatory bowel disease are at increased risk of colorectal and extra-intestinal cancer. However, the overall cancer risk in patients with Crohn's disease (CD) with perianal fistulas (PF) (CPF) and those with CD without PF (non-PF CD) is unclear.

OBJECTIVE

To describe the prevalence and incidence of cancer in patients with CPF and non-PF CD, and to estimate incidence rate ratio (IRR) of cancer between CPF and non-PF CD groups.

METHODS

A retrospective cohort study was conducted using the German InGef (Institute for Applied Health Research Berlin) research database. Patients with a CD record and PF from 1 January 2013 to 31 December 2014 were identified and followed up from 1 January 2015 until the first occurrence of cancer, end of health insurance contributing data, death, or end of study period (31 December 2020). Prevalence of any type of cancer including patients with CD diagnosed with cancer in the selection period and incidence of cancer excluding patients with CD diagnosed with cancer in the selection period were calculated.

RESULTS

In total, 10,208 patients with CD were identified. Of 824 patients with CPF (8.1%), 67 had had a malignancy (6-year period crude malignancy prevalence 8.13% [95% confidence interval (CI) 6.36%-10.21%]), which was lower than patients with non-PF CD (19.8% [95% CI 19%-20.6%]). Incidence (per 100,000 person-years) in patients with CPF was 1184 (95% CI 879-1561) and in non-PF CD was 2365 (95% CI 2219-2519). There was no significant difference in the adjusted IRR of cancer for the CPF group compared with the non-PF CD group (0.83 [95% CI 0.62-1.10]; p = 0.219).

CONCLUSION

There was no significant difference in the incidence of any cancer in patients with CPF compared with non-PF CD. However, patients with CPF had a higher numerical risk of cancer than the general German population.

Healthcare resource utilization and cost of pneumococcal disease in children in Germany, 2014-2019: a retrospective cohort study

BACKGROUND

Since the introduction of higher valency pneumococcal conjugate vaccines in 2009, recent estimates on the economic burden of pediatric pneumococcal disease (PD) in Germany have been lacking. This study estimates healthcare resource utilization (HCRU) and medical cost associated with PDs in children < 16 years old in Germany from 2014-2019.

METHODS

A nationally representative sample from the Institute for Applied Health Research (InGef) German claims database was used, covering approximately 5% of the total German population. Episodes of pneumococcal pneumonia (PP), all-cause pneumonia (ACP), invasive pneumococcal disease (IPD), and acute otitis media (AOM) in children aged < 16 years were identified using ICD-10-GM codes. HCRU was estimated from annual rates of outpatient visits, outpatient antibiotic prescriptions and inpatient admissions, divided by person-years (PY) at-risk. Average direct medical costs per episode were estimated as the total cost of all HCRU, divided by the total number of episodes. The Mann-Kendall test was used to assess monotonic time trends from 2014-2019.

RESULTS

 During 2014-2019, 916,805 children aged < 16 years were followed up for a total of 3,608,716 PY. The average costs per episode for out-versus inpatient care associated with PP and ACP were €67 (95% CI 58-76) versus €2,606 (95% CI 1,338-3,873), and €63 (95% CI 62-63) versus €620 (95% CI 598-641), respectively. For IPD, the average medical cost per episode for out-versus inpatients were €30 (95% CI 19-42) versus €6,051 (95% CI 3,323-8,779), respectively. There were no significant trends in HCRU or costs for IPD or pneumonia over the study period, except for a significant reduction in ACP outpatient visits. A significant decrease in rate of outpatient visits and antibiotic prescribing for recurrent AOM was observed, in addition to an increase in rates of hospital admissions for simple AOM. This was paralleled by a significant increase in inpatient costs per episode for treating AOM overall, and simple AOM, over the study period.

CONCLUSIONS

 The HCRU and cost per episode of pneumonia and IPD did not vary significantly from 2014-2019, but increased for AOM. The economic burden of pneumonia, IPD, and AOM remains substantial in Germany.

Incidence of acute otitis media from 2003 to 2019 in children ≤ 17 years in England

BACKGROUND

The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2006 and the 13-valent pneumococcal conjugate vaccine (PCV13) in 2010 in the UK. PCVs are active immunization for the prevention of invasive disease, pneumonia and acute otitis media (AOM) caused by Streptococcus pneumoniae in children. The aim of this observational study was to estimate incidence rates (IRs) of AOM in children ≤17 years from 2003 to 2019 in England, before and after the introduction of pneumococcal conjugate vaccines (PCVs).

METHODS

AOM episodes were identified using Read diagnosis codes in children aged ≤17 years in the Clinical Practice Research Datalink (CPRD) Gold database from 2003 to 2019. Annual IRs with 95% confidence intervals (CI) by age group were calculated as the number of episodes/person-years (PY) at risk. Interrupted time series analyses were conducted to estimate incidence rate ratios (IRR) across post-PCV7 (2007-2009), early post-PCV13 (2011-2014) and late post-PCV13 (2015-2019) periods compared to the pre-PCV7 period (2003-2005) using generalized linear models.

RESULTS

From 2003 to 2019, 274,008 all-cause AOM episodes were identified in 1,500,686 children. The overall AOM IR was 3690.9 (95% CI 3677.1-3704.8) per 100,000 PY. AOM IRs were highest in children aged < 5 years and decreased by age; < 2 years: 8286.7 (95% CI 8216.8-8357.1); 2-4 years: 7951.8 (95% CI 7902.5-8001.4); 5-17 years: 2184.4 (95% CI 2172.1-2196.8) (per 100,000 PY). Overall AOM IRs declined by 40.3% between the pre-PCV7 period and the late-PCV13 period from 4451.9 (95% CI 4418.1-4485.9) to 2658.5 (95% CI 2628.6-2688.7) per 100,000 PY, and across all age groups. IRRs indicated a significant decrease in AOM IRs in all the post-vaccination periods, compared to the pre-PCV7 period: post-PCV7 0.87 (95% CI 0.85-0.89), early post-PCV13 0.88 (95% CI 0.86-0.91), and late post-PCV13 0.75 (95% CI 0.73-0.78).

CONCLUSIONS

The AOM IRs declined during the 2003-2019 period; however, the clinical burden of AOM remains substantial among children ≤17 years in England.

Incidence of pneumococcal disease from 2003 to 2019 in children ≤17 years in England

BACKGROUND

Pneumococcal disease is a leading cause of communicable disease morbidity and mortality globally. We aimed to estimate invasive pneumococcal disease (IPD), pneumococcal pneumonia (PP) and all-cause pneumonia (ACP) incidence rates (IRs) in children aged 0-17 years in England from 2003 to 2019.

METHODS

A retrospective study in children ≤17 years old from 2003 to 2019 using the Clinical Practice Research Datalink (CPRD) Gold and Hospital Episodes Statistics Admitted Patient Care (HES APC) databases. IPD episodes were identified in hospital records (HES APC). PP (caused by Streptococcus pneumoniae only) and ACP episodes (caused by any pathogen) were identified in primary care (CPRD) and in hospital records (HES APC). Annual IRs by age-group were calculated as the number of episodes/person-years (PY) at risk, with 95% confidence intervals (95% CI). Interrupted time series analyses were conducted to assess changes in IRs across the post-PCV7 (2007-2009), early post-PCV13 (2011-2014) and late post-PCV13 (2015-2019) periods compared to the pre-PCV7 period (2003-2005) using generalized linear models.

RESULTS

170 IPD episodes, 769 PP episodes and 12,142 ACP episodes were identified in 1,500,686 children in 2003-2019. The overall IPD, PP and ACP IRs (per 100,000 PY) were 2.29 (95% CI 1.96-2.66), 10.34 (95% CI 9.62-11.10) and 163.37 (95% CI 160.47-166.30), respectively. The highest IPD, PP and ACP IRs were observed in children aged < 2 years compared to older children (2-4 and 5-17 years). IPD IRs decreased between the pre-PCV7 period and the late post-PCV13 period from 3.28 (95% CI 2.42-4.33) to 1.41 (95% CI 0.80-2.29), IRR 0.28 (95% CI 0.09-0.90), p-value 0.033. PP IRs declined between the pre-PCV7 period and the late post-PCV13 period from 14.65 (95% CI 12.77-16.72) to 3.87 (95% CI 2.81-5.20), IRR 0.19 (95% CI 0.09-0.38), p-value < 0.001. ACP IRs declined between the pre-PCV7 period and the late post-PCV13 period from 167.28 (95% CI 160.78-173.96) to 124.96 (95% CI 118.54-131.63), IRR 0.77 (95% CI 0.66-0.88), p-value < 0.001.

CONCLUSIONS

The clinical burden of IPD, PP and ACP declined in children in England aged 0-17 years between 2003 and 2019, especially in the late post-PCV13 period. This study highlights the importance of PCV vaccination in reducing the burden of PD and ACP in children in England.

Healthcare resource utilisation and cost of pneumococcal disease from 2003 to 2019 in children ≤17 years in England

OBJECTIVE

To estimate healthcare resource utilisation (HCRU) and costs associated with pneumococcal disease (PD) in children aged ≤17 years in England from 2003-2019.

METHODS

A retrospective study in children aged ≤17 years was conducted using the Clinical Practice Research Datalink Gold primary care database and Hospital Episodes Statistics Admitted Patient Care database from 2003-2019. Episodes of invasive pneumococcal disease (IPD) were identified in hospital, pneumococcal pneumonia (PP) and all-cause pneumonia (ACP) episodes in primary care and in hospital, and acute otitis media (AOM) episodes in primary care. General practitioner (GP) visits and inpatient admission yearly rates were calculated per 1,000 persons. The average inpatient and primary care cost per episode were calculated. The Mann-Kendall test was used to assess monotonic time trends.

RESULTS

1,500,686 children were followed from 2003-2019. The highest average inpatient cost per episode [£34,255 (95%CI 27,222-41,288)] was in IPD, followed by ACP [£3,549 (95%CI 3,405-3,693)] and PP [£1,498 (95%CI 1,153-1,843)]. The highest primary care costs per episode were in AOM [£48.7 (95%CI 48.7-48.7)], followed by PP [£38.4 (95%CI 37.0-39.7)] and ACP [£28.6 (95%CI 28.2-29.1)]. The highest inpatient admission and GP visits yearly rates were observed in children aged <2 years. Across years, a significant decrease in GP visits yearly rates was observed for PP, ACP and AOM in children overall (p-value<0.001). A decrease in primary care costs was observed for ACP (p-value<0.001). There was an increasing trend in AOM primary care costs (p-value<0.001). No significant trends were observed in inpatient admission yearly rates in PP, ACP or IPD and inpatient costs per episode in PP, ACP and IPD.

CONCLUSION

From 2003-2019, primary care HCRU and costs decreased (except for PP cost), but no trends in inpatient HCRU and costs were observed. The economic burden of pneumonia, IPD and AOM remains substantial in children aged ≤17 years in England.

Pneumococcal vaccination coverage in individuals (16-59 years) with a newly diagnosed risk condition in Germany

Background

Despite recommendations from the German Standing Committee on Vaccination (STIKO), pneumococcal vaccination coverage remains low in vulnerable populations. This study estimated the pneumococcal vaccination coverage rate (VCR) and timing among individuals aged 16–59 years in Germany who were recommended to receive pneumococcal vaccination, according to STIKO.

Methods

A retrospective cohort analysis was conducted using the German InGef database. Individuals aged 16 to 59 years diagnosed with at least one “at-risk” (chronic disease) or “high-risk” (e.g., immunocompromising) condition considered to be at-risk of pneumococcal infection were identified at the time of first diagnosis, between January 1, 2016 and December 31, 2018, and followed up until December 31, 2019. The percentage of cumulative pneumococcal VCR with 95% confidence interval (CI) was reported for each calendar year of follow-up.

Results

There were 334,292 individuals followed for a median of 2.38 (interquartile range (IQR) 1.63–3.13) person years. For individuals aged 16–59 years diagnosed with an incident risk condition in 2016, pneumococcal VCR increased from 0.44% (95% CI 0.41–0.48) in 2016 to 1.24% (95% CI 1.18–1.30) in 2019. In 2019, VCRs were higher in individuals with high-risk conditions compared with at-risk conditions (2.24% (95% CI 2.09–2.40) vs. 0.90% (95% CI 0.85–0.96)). In 2019, VCRs were higher in individuals aged 50 to 59 years compared with individuals aged 16 to 49 years (2.25% (95% CI 2.10–2.41) vs. 0.90% (95% CI 0.84–0.96)). Similar trends were observed in individuals with newly diagnosed risk conditions identified in 2017 and in 2018. Older age, influenza vaccination and increasing number of risk conditions increased the likelihood of pneumococcal vaccination. Median time to vaccination from diagnosis of the risk condition was shorter for high-risk conditions (369.5 days (IQR 155.8–702.0)) compared to at-risk conditions (435.5 days (IQR 196.3–758.8)).

Conclusion

Despite recommendations from STIKO, pneumococcal vaccination coverage remains very low and with long delays in vulnerable individuals aged 16–59 in Germany. Further efforts are required to increase immunization levels and shorten time to vaccination among individuals 16–59 years of age developing conditions with higher susceptibility to pneumococcal infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07736-1.

Incidence of acute otitis media in children < 16 years old in Germany during 2014-2019

BACKGROUND

Acute otitis media (AOM) remains a common infection in children despite the introduction of pneumococcal conjugate vaccines. This study estimated AOM incidence rates (IRs) over time in children < 16 years old in Germany following PCV13 introduction.

METHODS

AOM episodes were identified in the InGef healthcare claims database from 2014-2019 in children aged < 16 years. Each AOM episode was classified as either simple or recurrent. Recurrent AOM was defined as 3 or more episodes identified within a 6-month period; or 4 or more episodes within a 12-month period with at least one episode in the prior 6 months. AOM-related surgical procedures within 12 months and complications within 21 days of an AOM episode were also identified. Annual IRs were calculated as number of episodes/child-years (CY) at risk. 95% Confidence intervals (95%CI) were calculated using the Wilson method. The Mann-Kendall test was used to assess trends over time.

RESULTS

Between 2014 and 2019, the study population comprised 916,805 children with 327,726 AOM episodes, of which 15% (49,011) of all episodes were identified as recurrent AOM and 85% (278,715) as simple AOM. There were significant declines in AOM (p = 0.003) in the study population overall and in all age groups over the study period; from 101 (95%CI 101-102)/1000 CY to 79 (95%CI 78-80)/1000 CY in the total study population, from 209 (95%CI 206-212)/1000 CY to 147 (95%CI 145-150)/1000 CY in < 2-year-olds, from 239 (95%CI 237-242) to 179 (95%CI 177-182)/1000 CY in 2-4-year-olds, and from 50 (95%CI 49-50) to 38 (95%CI 37-39)/1000 CY in 5-15-year-olds. No significant trends were identified for AOM-related surgical procedures over the study period; however, AOM-related complications overall increased (p = 0.003).

CONCLUSION

Between 2014 and 2019, AOM incidence overall declined in children aged 0-15 years in Germany. Over the study period, the incidence of complicated AOM cases increased, however the incidence of AOM-related surgical procedures remained constant. Despite the impact of PCV13, the burden associated with AOM in Germany remains substantial.

Antipsychotic treatment patterns in Alzheimer's disease patients with agitation: a cohort study using the UK clinical practice research datalink

OBJECTIVES

There is a lack of robust epidemiological evidence on antipsychotic (AP) use in patients with agitation in Alzheimer's disease (AD). Authors studied AP use in patients with AD and agitation and compared their use with patients with other or no neuropsychiatric symptoms (NPS).

METHODS

A retrospective cohort study in the UK Clinical Practice Research Datalink, included patients with AD between January 1^st, 2015, and December 31^st, 2017. AP use was compared between patients with agitation, other types of NPS and no NPS.

RESULTS

There were 24,464 patients with AD, median follow-up of 1.1 years (interquartile range [IQR] 0.5-2.1), and median age 83 years (78-88). A larger percentage of patients with agitation (n = 2432) were prescribed APs (38.2%) than other NPS (n = 13,076, 20.4%) and no NPS (n = 11,816, 12.2%). Compared to patients with no NPS, adjusted hazard ratios for AP use were 3.45 (95% CI 2.86-4.17) for patients with agitation and 1.31 (95% CI 1.19-1.44) for patients with other NPS. Among users of APs, the treatment discontinuation rate at six months was 44.8% in patients with agitation (other NPS 57.1%; no NPS 63.5%).

CONCLUSIONS

Patients with AD and agitation were frequently prescribed APs and for long periods in routine clinical practice in the UK. The high real-life usage of APs suggests that physicians prefer using APs for the treatment of agitation despite recommendations against their long-term use. These data support a need for AP therapies that better address known safety concerns with currently used APs to treat agitation in elderly patients with AD.

A Prospective Open-Label Observational Study of a Buffered Soluble 70 mg Alendronate Effervescent Tablet on Upper Gastrointestinal Safety and Medication Errors: The GastroPASS Study

Upper gastrointestinal (GI) side effects are a main reason for discontinuing bisphosphonate treatment, an important therapeutic option for osteoporosis patients. Consequently, the development of novel formulations with improved tolerability is warranted. In this multicenter prospective, observational, postauthorization safety study conducted in Italy and Spain, postmenopausal women (PMW) with osteoporosis (naïve to bisphosphonates) were treated weekly with a buffered soluble alendronate 70 mg effervescent (ALN-EFF) tablet (Binosto®) and followed for 12 ± 3 months. Information was collected on adverse events (AEs), medication errors, persistence, and compliance using the Morisky-Green questionnaire. Patients (N = 1028) aged 67 ± 9 years (mean ± SD) received ALN-EFF weekly. The cumulative incidence of upper GI AEs (oesophageal toxicity, gastritis, gastric ulcers, and duodenitis) related to ALN-EFF (primary endpoint) was 9.6% (95% confidence interval [CI] 7.9-11.6%), the vast majority being of mild intensity. The most frequently occurring upper GI AEs related to ALN-EFF were dyspepsia (2.7%), gastroesophageal reflux disease (2.4%), and nausea (2.2%). None of the relevant upper GI AEs listed in the primary endpoint and no serious AEs were reported. At least one medication error occurred in 29.9% (95% CI 27.1-32.8%) of patients. However, the majority of medication errors were associated with administration instructions applicable to any oral bisphosphonate and only seven medication errors were associated with the ALN-EFF formulation. ALN-EFF was discontinued in 209 of 1028 (20.3%) patients. The most frequent reasons for discontinuation were AEs related to ALN-EFF (46.9%) and patients' decision (42.6%). Compliance with ALN-EFF was high, reflected by a mean Morisky-Green score of 92.8 ± 18.6. PMW with osteoporosis treated with ALN-EFF in a real-world setting experienced few upper GI AEs. In addition, they had a low discontinuation and high compliance compared with other formulations, suggesting that ALN-EFF may increase patient satisfaction and therefore long-term adherence and efficacy. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Localised neuropathic pain in the primary care setting: a cross-sectional study of prevalence, clinical characteristics, treatment patterns, quality of life and sleep performance

BACKGROUND

Localised Neuropathic Pain (LNP) is challenging to diagnose and manage in primary care.

OBJECTIVE

To describe clinical characteristics, treatment patterns, quality of life and sleep performance of patients with LNP and estimate its prevalence in primary care.

METHODS

Cross-sectional study in 4 European countries. Patients were identified using a screening tool for LNP. Patients completed the EQ-5D VAS score and Chronic Pain Sleep Inventory (CPSI).

RESULTS

There were 1030 LNP patients for analysis. They presented a median pain intensity of 6.0 (IQR 4.0-7.0) with a median duration of 30.9 months (IQR 12.0-75.3), despite 97% receiving pain treatment. Main sites affected were the limbs (62% upper/58% lower) and spine (41%). Main aetiologies were neuropathic low back pain (47%), post-surgical neuropathic pain (17%), and diabetic poly-neuropathy (12%). Thirty percent received a single analgesic (2% topical), while combinations comprised 43% systemic-systemic, 24% topical-systemic, 1% topical-topical. Medications included NSAIDs (45%), anticonvulsants (38%), WHO step 2 opioids (35%), and topical analgesics (27%). In the previous 6 months, 40% had switched treatment. The mean (SD) EQ-5D VAS score was 58 (22.3) and the mean (SD) EQ-5D summary score (UK tariff) was 0.62 (0.25). Patients had a CPSI mean index of 41/100, and sleeping pills were used by 33% of patients. The standardized prevalence of LNP by age and sex was 2.01% in the general population and 43.3% among chronic pain patients.

CONCLUSIONS

Many LNP patients reported pain intensities of six on a ten-point scale in average for durations longer than 2.5 years, with quality of life and sleep performance affected, with frequent treatment combinations and switches, suggesting suboptimal pain management.

Association of anthropometry and weight change with risk of dementia and its major subtypes: A meta-analysis consisting 2.8 million adults with 57 294 cases of dementia

Uncertainty exists regarding the relation of body size and weight change with dementia risk. As populations continue to age and the global obesity epidemic shows no sign of waning, reliable quantification of such associations is important. We examined the relationship of body mass index, waist circumference, and annual percent weight change with risk of dementia and its subtypes by pooling data from 19 prospective cohort studies and four clinical trials using meta-analysis. Compared with body mass index-defined lower-normal weight (18.5-22.4 kg/m2 ), the risk of all-cause dementia was higher among underweight individuals but lower among those with upper-normal (22.5-24.9 kg/m2 ) levels. Obesity was associated with higher risk in vascular dementia. Similarly, relative to the lowest fifth of waist circumference, those in the highest fifth had nonsignificant higher vascular dementia risk. Weight loss was associated with higher all-cause dementia risk relative to weight maintenance. Weight gain was weakly associated with higher vascular dementia risk. The relationship between body size, weight change, and dementia is complex and exhibits non-linear associations depending on dementia subtype under scrutiny. Weight loss was associated with an elevated risk most likely due to reverse causality and/or pathophysiological changes in the brain, although the latter remains speculative.

Burden of disease from shingles and post-herpetic neuralgia in the over 80 year olds in the UK

BACKGROUND

The current UK vaccination programme for herpes zoster (HZ) excludes people aged ≥80 years. This study aimed to quantify the number of individuals ≥80 years who missed HZ vaccination and the consequent epidemiological and economic burden of HZ and post-herpetic neuralgia (PHN).

METHODS

Immunocompetent individuals aged ≥80 years between 1st September 2013 and 31st December 2017 in the Clinical Practice Research Datalink were selected and linked to Hospital Episodes Statistics, where available. Rates of HZ and PHN and healthcare resource utilisation were investigated for the overall study population and by age group (80-84, 85-89, ≥90 years old) and the burden of HZ and PHN was projected to the UK population.

RESULTS

4,858 HZ episodes and 464 PHN cases were identified in 255,165 individuals over 576,421 person-years (PY). Rates of HZ and PHN were 8.43 (95% confidence interval [CI] 8.19-8.66) and 0.80 (0.73-0.87) per 1,000 PY respectively and lowest in those aged ≥90 (HZ rate 7.37/1,000 PY; PHN rate 0.56/1,000 PY). Within HZ episodes, 10.27% of GP visits, 5.82% of prescribed medications and 21.65% of hospitalisations were related to HZ/PHN. Median length of hospitalisation increased from 7.0 days for all-cause to 10.5 days for HZ/PHN related hospitalisations. Individuals ≥90 stayed in hospital a median of 3-4 days longer than younger groups. Approximately 2.23 million individuals in the UK missed HZ vaccination since 2013 (1.86 million had never been eligible and 365,000 lost eligibility for HZ vaccination), resulting in an estimated 43,149 HZ episodes.

CONCLUSION

This study highlights the impact of the 80-year upper age limit policy on the health system. Our study estimates that 2.23 million individuals in the UK may have lost the opportunity to be vaccinated and that their burden of HZ and PHN remains high, especially among the very elderly.

Pre/post effectiveness evaluation of updated additional risk minimisation measures for an orphan disease: Myozyme (alglucosidase alfa) Safety Information Packet

BACKGROUND

The alglucosidase alfa (Myozyme®) Safety Information Packet ("previous SIP") was updated to improve readability and content ("updated SIP"). We compared the previous and updated SIPs.

METHODS

A two-wave pre-post multicountry survey was conducted among health care professionals (HCPs) who prescribed or monitored patients on alglucosidase alfa in the largest European Union ("EU5") countries and Poland. Wave (W) 2 started 15 months after completion of W1 and the implementation of the updated SIP. Changes between the waves were analysed.

RESULTS

Forty-six HCPs (34 physicians/12 nurses) participated in W1 and 52 in W2 (42 physicians/10 nurses); 22 participated in both waves. Nonsignificant differences were observed between waves 1 and 2 for awareness (75.6% in W1 and 82.4% in W2) and receipt (77.7% in W1 and 74.5% in W2) of the SIP, reading (88.6% in W1 and 89.5% in W2) and usage (88.2% in W1 and 89.5% in W2) among receivers of the SIP, or the overall knowledge about immunological testing (61.1% in W1 vs 55.1% in W2). Frequency of performance of immunological testing was significantly higher in W2 than in W1 (50.3% vs 34.4%; P = .024) with a tendency for increases in the appropriate performance of all types of testing in W2.

CONCLUSIONS

Both versions of the SIP showed relatively high awareness, receipt, reading, and usage, with an overall trend for most measures to improve numerically in W2. The updated SIP did not require further changes.

Are risk minimization measures for approved drugs in Europe effective? A systematic review

Objectives: The effectiveness of risk minimization measures (RMMs) requires evaluation. This study aims to evaluate the results of cross-sectional surveys assessing the effectiveness of RMMs in Europe (EU RM Surveys) and review the regulatory consequences. Methods: The authors searched for study reports and manuscripts of completed EU RM surveys in the EU PAS Register, MEDLINE, and Google between 01/2011 and 01/2018. Regulatory responses were extracted from Assessment Reports. Random effects models to combine proportions were used. Results: Twenty-four EU RM surveys were identified. Twenty-three studies targeted health-care professionals (HCPs). The pre-specified sample size was reached in 52% of studies. HCP participation was 5% defined as completers/invited and 89% for completers/eligible. Receipt of materials was recalled by 60% of HCPs and 77% of items scored knowledge >60%. Eight studies targeted patients/caregivers. The pre-specified sample size was reached in only two. Participation was 93%, defined as completers/eligible. Materials were received by 50-80% of patients and read by over 90%. Patients only scored knowledge >60% in 38% of items. Further action was requested by regulators in 59% of studies. Conclusion: Surveys are necessary to evaluate many RMMs. Challenges remain in the design, conduct, and reporting of these studies which may benefit from the use of standard definitions and further guidance on reporting. EU PAS Register: http://www.encepp.eu/encepp/viewResource.htm?id=23435.

Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

A review of studies evaluating the effectiveness of risk minimisation measures in Europe using the European Union electronic Register of Post-Authorization Studies

PURPOSE

An important element of risk management is the planning and implementation of risk minimisation measures (RMMs) and the evaluation of their effectiveness by process or outcome indicators. The aim of this review is to summarize the characteristics of risk minimisation (RM) effectiveness studies in Europe and provide an overview of RMMs and their effectiveness.

METHODS

This was a qualitative review of RM effectiveness studies in the European Union electronic Register of Post-Authorization Studies (EU PAS Register); data extracted included study design, population, sample size, data sources, drug information, RMMs, study period, indicators, and their reported effectiveness.

RESULTS

Of the 872 records in the EU PAS Register, 19 studies evaluating the effectiveness of RMMs were included. Eleven were cross-sectional surveys and 8 used secondary data sources. Eighty-nine percent (17/19) evaluated additional RMMs (used when routine RMMs are considered insufficient), and 36% (7/19) evaluated changes in routine RMMs (applicable to all medicinal products). A total of 42 effectiveness indicators were identified: 18 process and 24 outcomes. Half of the indicators (21/42) were successful; 2% (1/42) indicators were partially successful; 17% (7/42) indicators were inconclusive. Effectiveness of the remaining 31% (13/42) indicators could not be determined owing to limited information. The United Kingdom was the most frequent country for the conduct of RM effectiveness studies.

CONCLUSIONS

Most of the included studies evaluated additional RMMs. Half of the effectiveness indicators (process and/or outcome) were reported as successful. This review provides evidence to support the development of future guidance on the effectiveness of RM in Europe.

A Retrospective Study of the Clinical Burden of Hospitalized All-Cause and Pneumococcal Pneumonia in Canada

Background. Routine vaccination against Streptococcus pneumoniae is recommended in Canada for infants, the elderly, and individuals with chronic comorbidity. National incidence and burden of all-cause and pneumococcal pneumonia in Canada (excluding Quebec) were assessed. Methods. Incidence, length of stay, and case-fatality rates of hospitalized all-cause and pneumococcal pneumonia were determined for 2004-2010 using ICD-10 discharge data from the Canadian Institutes for Health Information Discharge Abstract Database. Population-at-risk data were obtained from the Statistics Canada census. Temporal changes in pneumococcal and all-cause pneumonia rates in adults ≥65 years were analyzed by logistic regression. Results. Hospitalization for all-cause pneumonia was highest in children <5 years and in adults >70 years and declined significantly from 1766/100,000 to 1537/100,000 per year in individuals aged ≥65 years (P < 0.001). Overall hospitalization for pneumococcal pneumonia also declined from 6.40/100,000 to 5.08/100,000 per year. Case-fatality rates were stable (11.6% to 12.3%). Elderly individuals had longer length of stay and higher case-fatality rates than younger groups. Conclusions. All-cause and pneumococcal pneumonia hospitalization rates declined between 2004 and 2010 in Canada (excluding Quebec). Direct and indirect effects from pediatric pneumococcal immunization may partly explain some of this decline. Nevertheless, the burden of disease from pneumonia remains high.

BMI and risk of dementia in two million people over two decades: a retrospective cohort study

BACKGROUND

Dementia and obesity are increasingly important public health issues. Obesity in middle age has been proposed to lead to dementia in old age. We investigated the association between BMI and risk of dementia.

METHODS

For this retrospective cohort study, we used a cohort of 1,958,191 individuals derived from the United Kingdom Clinical Practice Research Datalink (CPRD) which included people aged 40 years or older in whom BMI was recorded between 1992 and 2007. Follow-up was until the practice's final data collection date, patient death or transfer out of practice, or first record of dementia (whichever occurred first). People with a previous record of dementia were excluded. We used Poisson regression to calculate incidence rates of dementia for each BMI category.

FINDINGS

Our cohort of 1,958,191 people from UK general practices had a median age at baseline of 55 years (IQR 45-66) and a median follow-up of 9·1 years (IQR 6·3-12·6). Dementia occurred in 45,507 people, at a rate of 2·4 cases per 1000 person-years. Compared with people of a healthy weight, underweight people (BMI <20 kg/m(2)) had a 34% higher (95% CI 29-38) risk of dementia. Furthermore, the incidence of dementia continued to fall for every increasing BMI category, with very obese people (BMI >40 kg/m(2)) having a 29% lower (95% CI 22-36) dementia risk than people of a healthy weight. These patterns persisted throughout two decades of follow-up, after adjustment for potential confounders and allowance for the J-shape association of BMI with mortality.

INTERPRETATION

Being underweight in middle age and old age carries an increased risk of dementia over two decades. Our results contradict the hypothesis that obesity in middle age could increase the risk of dementia in old age. The reasons for and public health consequences of these findings need further investigation.

FUNDING

None.

Trends in utilization and off-label use of polyethylene glycol 4000 laxatives and the prevalence of constipation in children in France

Purpose:

To determine trends in utilization and off-label use of polyethylene glycol (PEG) 4000 in children and to determine the prevalence of constipation.

Methods:

Retrospective cross-sectional analyses were conducted from 1997 to 2007 in a French health care database comprising general practitioners and pediatricians. Patients prescribed PEG 4000 (Forlax^®; Ipsen Pharma, Paris, France) were used to assess PEG 4000 use; constipation was defined by a diagnosis of constipation or use of any laxative. Analyses used linear regression models to fit trends over time.

Results:

The study sample consisted of a nationally representative sample of 1200 general practitioners with 1.6 million patient medical records and 100 pediatricians with 70,000 patient medical records. Data were available from 1997 to 2007 for general practitioners and from 2003 to 2007 for pediatricians and were extrapolated to the national level. Among both groups of physicians there were statistically significant increases in the number of patients prescribed 4 g. For the 10 g dose, there was a decline among pediatricians. The largest increases were in children aged 0–8 years and in females. The prevalence of constipation in children aged 0–18 years was 4%.

Conclusion:

There has been an increase in the use of PEG 4000 laxative in children, particularly in the younger ages and in females. Use of the 4 g dose has increased. There was considerable off-label use of PEG 4000 in children aged 0–8 years before the introduction of the 4 g pediatric dose, which reflected clinical need.

Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies

BACKGROUND

The main associations of body-mass index (BMI) with overall and cause-specific mortality can best be assessed by long-term prospective follow-up of large numbers of people. The Prospective Studies Collaboration aimed to investigate these associations by sharing data from many studies.

METHODS

Collaborative analyses were undertaken of baseline BMI versus mortality in 57 prospective studies with 894 576 participants, mostly in western Europe and North America (61% [n=541 452] male, mean recruitment age 46 [SD 11] years, median recruitment year 1979 [IQR 1975-85], mean BMI 25 [SD 4] kg/m(2)). The analyses were adjusted for age, sex, smoking status, and study. To limit reverse causality, the first 5 years of follow-up were excluded, leaving 66 552 deaths of known cause during a mean of 8 (SD 6) further years of follow-up (mean age at death 67 [SD 10] years): 30 416 vascular; 2070 diabetic, renal or hepatic; 22 592 neoplastic; 3770 respiratory; 7704 other.

FINDINGS

In both sexes, mortality was lowest at about 22.5-25 kg/m(2). Above this range, positive associations were recorded for several specific causes and inverse associations for none, the absolute excess risks for higher BMI and smoking were roughly additive, and each 5 kg/m(2) higher BMI was on average associated with about 30% higher overall mortality (hazard ratio per 5 kg/m(2) [HR] 1.29 [95% CI 1.27-1.32]): 40% for vascular mortality (HR 1.41 [1.37-1.45]); 60-120% for diabetic, renal, and hepatic mortality (HRs 2.16 [1.89-2.46], 1.59 [1.27-1.99], and 1.82 [1.59-2.09], respectively); 10% for neoplastic mortality (HR 1.10 [1.06-1.15]); and 20% for respiratory and for all other mortality (HRs 1.20 [1.07-1.34] and 1.20 [1.16-1.25], respectively). Below the range 22.5-25 kg/m(2), BMI was associated inversely with overall mortality, mainly because of strong inverse associations with respiratory disease and lung cancer. These inverse associations were much stronger for smokers than for non-smokers, despite cigarette consumption per smoker varying little with BMI.

INTERPRETATION

Although other anthropometric measures (eg, waist circumference, waist-to-hip ratio) could well add extra information to BMI, and BMI to them, BMI is in itself a strong predictor of overall mortality both above and below the apparent optimum of about 22.5-25 kg/m(2). The progressive excess mortality above this range is due mainly to vascular disease and is probably largely causal. At 30-35 kg/m(2), median survival is reduced by 2-4 years; at 40-45 kg/m(2), it is reduced by 8-10 years (which is comparable with the effects of smoking). The definite excess mortality below 22.5 kg/m(2) is due mainly to smoking-related diseases, and is not fully explained.

Risk of ischaemic cardiovascular events from selective cyclooxygenase-2 inhibitors in osteoarthritis

PURPOSE

Most previous observational studies assessing cardiovascular risk associated with Cox-2 inhibitors (Cox-2is) used a case control approach, limiting the assessment of absolute risk by disease group and effect of duration of exposure. We conducted a retrospective cohort study in patients with osteoarthritis.

METHODS

Using the Life-link US claims database, all subjects had at least five years history in the database. Exposure was defined as the first chronic period of Cox-2i (celecoxib, rofecoxib or valdecoxib) or naproxen use. Non-users and non-chronic users of non-steroidal anti-inflammatory drug (NSAID)/Cox-2i within the osteoarthritis cohort served as the reference. The primary outcome was myocardial infarction and ischaemic stroke.

RESULTS

A cohort of 16,580 subjects were chronically exposed to celecoxib, 9800 received rofecoxib, 2907 received naproxen and 51,539 were non-chronically exposed controls. With a median follow up of 506 days, there were 2116 ischaemic events for the entire cohort. The strongest predictors of AMI/ ischaemic stroke risk were history of ischaemic stroke (HR 2.34, 2.12-2.59) and age 65+ years (HR 2.28, 2.07-2.52). For rofecoxib, (HR 1.25,1.04-1.50), the attributable risk varied from 3 per 1000 patients years in individuals aged under 65 years with no history of CVD to 19 per 1000 patients years in older individuals with a history of CVD. The hazard ratios did not change over time. Celecoxib and naproxen were not associated with increased risks.

CONCLUSIONS

The attributable risk for rofecoxib varied substantially with the underlying cardiovascular risk profile, being lower in clinical trial than in clinical practice populations.

Blood cholesterol and vascular mortality by age, sex, and blood pressure: a meta-analysis of individual data from 61 prospective studies with 55,000 vascular deaths

BACKGROUND

Age, sex, and blood pressure could modify the associations of total cholesterol (and its main two fractions, HDL and LDL cholesterol) with vascular mortality. This meta-analysis combined prospective studies of vascular mortality that recorded both blood pressure and total cholesterol at baseline, to determine the joint relevance of these two risk factors.

METHODS

Information was obtained from 61 prospective observational studies, mostly in western Europe or North America, consisting of almost 900,000 adults without previous disease and with baseline measurements of total cholesterol and blood pressure. During nearly 12 million person years at risk between the ages of 40 and 89 years, there were more than 55,000 vascular deaths (34,000 ischaemic heart disease [IHD], 12,000 stroke, 10,000 other). Information about HDL cholesterol was available for 150,000 participants, among whom there were 5000 vascular deaths (3000 IHD, 1000 stroke, 1000 other). Reported associations are with usual cholesterol levels (ie, corrected for the regression dilution bias).

FINDINGS

1 mmol/L lower total cholesterol was associated with about a half (hazard ratio 0.44 [95% CI 0.42-0.48]), a third (0.66 [0.65-0.68]), and a sixth (0.83 [0.81-0.85]) lower IHD mortality in both sexes at ages 40-49, 50-69, and 70-89 years, respectively, throughout the main range of cholesterol in most developed countries, with no apparent threshold. The proportional risk reduction decreased with increasing blood pressure, since the absolute effects of cholesterol and blood pressure were approximately additive. Of various simple indices involving HDL cholesterol, the ratio total/HDL cholesterol was the strongest predictor of IHD mortality (40% more informative than non-HDL cholesterol and more than twice as informative as total cholesterol). Total cholesterol was weakly positively related to ischaemic and total stroke mortality in early middle age (40-59 years), but this finding could be largely or wholly accounted for by the association of cholesterol with blood pressure. Moreover, a positive relation was seen only in middle age and only in those with below-average blood pressure; at older ages (70-89 years) and, particularly, for those with systolic blood pressure over about 145 mm Hg, total cholesterol was negatively related to haemorrhagic and total stroke mortality. The results for other vascular mortality were intermediate between those for IHD and stroke.

INTERPRETATION

Total cholesterol was positively associated with IHD mortality in both middle and old age and at all blood pressure levels. The absence of an independent positive association of cholesterol with stroke mortality, especially at older ages or higher blood pressures, is unexplained, and invites further research. Nevertheless, there is conclusive evidence from randomised trials that statins substantially reduce not only coronary event rates but also total stroke rates in patients with a wide range of ages and blood pressures.

Cancer risks in thiazolidinedione users compared to other anti-diabetic agents

PURPOSE

We conducted three nested case-control studies to evaluate the risk of breast, colon, and prostate cancers developing in patients exposed to thiazolidinediones (TZDs) compared with other anti-diabetic agents.

METHODS

Cancer cases were matched to five controls by age, gender, calendar year, and time in the database from a cohort of 1 26 971 diabetic patients taking anti-diabetic medication in the US Integrated Healthcare Information Services database. Five hundred thirteen breast cancer cases were matched with 2557 controls, 408 cases of colon cancer were matched with 2027 controls and 643 cases of prostate cancer were matched with 3176 controls. Exposure to an anti-diabetic agent within 90 days preceding the index date was defined as recent exposure and at any time during the follow-up was defined as ever exposed.

RESULTS

The adjusted odds ratios and 95%CI of cancer from ever exposure to TZDs compared to oral monotherapy, oral dual therapy, oral triple therapy, insulin monotherapy, insulin and oral therapy and all non-TZD anti-diabetic agents were, respectively for breast cancer: 0.91 (0.69-1.20), 0.80 (0.56-1.14), 0.87 (0.32-2.35), 1.27 (0.61-2.67), 0.71 (0.36-1.37), 0.89 (0.68-1.15); for colon cancer: 1.06 (0.80-1.40), 1.12 (0.77-1.63), 1.73 (0.39-7.78), 4.46 (1.05-19.00), 1.06 (0.50-2.26) 1.03 (0.80-1.32) and for prostate cancer: 1.08 (0.85-1.37), 0.89 (0.66-1.21); 0.82 (0.33-2.06); 1.80 (0.79-4.07), 1.10 (0.55-2.18), 1.04 (0.83-1.31). Results for exposure within 90 days of the date of the cancer were similar.

CONCLUSIONS

Our findings suggest that the effect of TZDs on the likelihood of development of the cancers studied (colon, prostate and breast) appears to be neutral and do not support a beneficial or deleterious effect of TZD on the cancers studied.

A multicentre longitudinal observational study of changes in self reported health status in people with Parkinson's disease left untreated at diagnosis

BACKGROUND

The issue of when to start treatment in Parkinson's disease (PD) remains controversial. Some favour treatment at diagnosis while others opt for a "wait and watch" policy. The effect of the latter policy on the self reported health status of people with PD is unknown.

AIMS

To record self reported health status through longitudinal use of a validated PD specific questionnaire (PDQ-39) in untreated PD patients in multiple centres in the UK. To compare patients who were left untreated with those who were offered treatment during follow-up.

METHODS

A multicentre, prospective, "real life" observational audit based study addressing patient reported outcomes in relation to self reported health status and other sociodemographic details.

RESULTS

198 untreated PD were assessed over a mean period of 18 months. During two follow-up assessments, the self reported health status scores in all eight domains of the PDQ-39 and the overall PDQ-39 summary index worsened significantly (p<0.01) in patients left untreated. In a comparative group in whom treatment was initiated at or soon after diagnosis, there was a trend towards improvement in self reported health status scores after treatment was started.

CONCLUSIONS

This study addresses for the first time self reported health status, an indicator of health related quality of life, in untreated PD. The findings may strengthen the call for re-evaluation of the policy to delay treatment in newly diagnosed patients with PD.

Apolipoproteins as Predictors of Ischaemic Stroke in Patients with a Previous Transient Ischaemic Attack

BACKGROUND

Weak associations between total and LDL cholesterol and ischaemic stroke compared with coronary heart disease (CHD) are at odds with the similar effectiveness of statin drugs in preventing ischaemic stroke and CHD, suggesting that other lipid sub-fractions that are affected by statins might be better predictors of ischaemic stroke. Apolipoprotein B levels are reduced by statins and are a stronger predictor of CHD than total and LDL cholesterol in patients both on and off statins. However, there are very few published data on apolipoproteins and stroke risk and no studies in patients with previous transient ischaemic attack (TIA).

METHODS

We performed a prospective cohort study of the associations of baseline total cholesterol, LDL, HDL, apolipoproteins A1 and B (apo A1; apo B) and risk of ischaemic stroke in 261 patients with previous TIA. Cox proportional hazards models were used to determine crude and multivariate-adjusted hazard ratios (HR) above versus below median values at 10-years follow-up.

RESULTS

The apo B/apo A1 ratio was the strongest independent predictor of ischaemic stroke (HR=2.94, 95% CI 1.43-5.88, p=0.003) followed by apo B (HR=2.26, 95% CI 1.16-4.38, p=0.02). The associations between total cholesterol, LDL, HDL, LDL/HDL ratio and apo A1 and ischaemic stroke risk did not reach statistical significance.

CONCLUSIONS

Apo B and the apo B/apo A1 ratio are predictive of ischaemic stroke in patients with previous TIA. Further studies are required to determine whether the prognostic value of apolipoprotein levels is maintained in patients on statins.

Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies

BACKGROUND

The age-specific relevance of blood pressure to cause-specific mortality is best assessed by collaborative meta-analysis of individual participant data from the separate prospective studies.

METHODS

Information was obtained on each of one million adults with no previous vascular disease recorded at baseline in 61 prospective observational studies of blood pressure and mortality. During 12.7 million person-years at risk, there were about 56000 vascular deaths (12000 stroke, 34000 ischaemic heart disease [IHD], 10000 other vascular) and 66000 other deaths at ages 40-89 years. Meta-analyses, involving "time-dependent" correction for regression dilution, related mortality during each decade of age at death to the estimated usual blood pressure at the start of that decade.

FINDINGS

Within each decade of age at death, the proportional difference in the risk of vascular death associated with a given absolute difference in usual blood pressure is about the same down to at least 115 mm Hg usual systolic blood pressure (SBP) and 75 mm Hg usual diastolic blood pressure (DBP), below which there is little evidence. At ages 40-69 years, each difference of 20 mm Hg usual SBP (or, approximately equivalently, 10 mm Hg usual DBP) is associated with more than a twofold difference in the stroke death rate, and with twofold differences in the death rates from IHD and from other vascular causes. All of these proportional differences in vascular mortality are about half as extreme at ages 80-89 years as at ages 40-49 years, but the annual absolute differences in risk are greater in old age. The age-specific associations are similar for men and women, and for cerebral haemorrhage and cerebral ischaemia. For predicting vascular mortality from a single blood pressure measurement, the average of SBP and DBP is slightly more informative than either alone, and pulse pressure is much less informative.

INTERPRETATION

Throughout middle and old age, usual blood pressure is strongly and directly related to vascular (and overall) mortality, without any evidence of a threshold down to at least 115/75 mm Hg.

Corticosteroids for acute ischaemic stroke

BACKGROUND

Much of the brain swelling in ischaemic stroke is due to cytotoxic oedema, which is related to cell membrane dysfunction. Early treatment with corticosteroids may help reduce the swelling and improve the outcomes after a stroke.

OBJECTIVES

The objective of this review was to assess the effect of corticosteroids in acute presumed ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched: 10 April 2001) and contacted investigators in the field.

SELECTION CRITERIA

Published randomised trials comparing corticosteroids with placebo or control in people with acute (presumed or definite) ischaemic stroke. Trials were included if treatment began within 48 hours of stroke onset and if clinical outcome was assessed.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied the inclusion criteria, assessed trial quality and extracted the data.

MAIN RESULTS

Seven trials involving 453 people were included. Details of trial quality that may relate to bias were not available from most trials. No difference was shown in the odds of death within one year (odds ratio 1.08, 95% confidence interval 0.68 to 1.72). Treatment did not appear to improve functional outcome in survivors. Six trials reported neurological impairment but pooling the data was impossible because no common scale or time interval was used. The results were inconsistent between individual trials. The only adverse effects reported were small numbers of gastrointestinal bleeds, infections and deterioration of hyperglycaemia across both groups. Results unchanged since last update.

REVIEWER'S CONCLUSIONS

There is not enough evidence to evaluate corticosteroid treatment for people with acute presumed ischaemic stroke. Conclusions unchanged since last update.

Experimental approaches and drugs in development for the treatment of dementia

Treatment of dementia can be divided as symptomatic treatment of cognitive or non-cognitive symptoms and the treatment of underlying pathology. In the last decade the thrust of symptomatic treatment of Alzheimer's disease (AD) has been enhancement of cholinergic transmission. Besides the acetycholinesterase inhibitors (AChE-I) currently in use, cholinergic agonists and enhancers are in development. Other therapeutic approaches directed towards neurotransmitter substitution or modulation include serotoninergic, noradrenergic substances, neuropeptides and those acting via excitatory amino acid receptors, such as ampakines or NMDA antagonists. Introduction of atypical neuroleptics represents the most recent development in the treatment of behavioural symptoms. Efforts to treat the underlying pathology are based on modulation of APP processing in order to decrease the accumulation of beta-amyloid, those to decrease tau hyperphosphorylation, use of nerve growth factors and those based on Apo-E modulation. Potential use of oestrogens and NSAIDs are also under investigation. Recently, vaccination with amyloid-beta peptide has been reported to be effective in an animal model of AD, this putative vaccine is now in clinical trials. Likewise, recent studies suggest that some statins may have a prophylactic effect.

Economic evaluation alongside n-of-1 trials: getting closer to the margin

The n-of-1 trial is a particularly flexible form of randomized controlled trial that involves a single patient receiving multiple episodes of alternative therapies. Although n-of-1 trials are only applicable in certain treatment areas, the collection of economic data within such trials may provide unique advantages. This paper illustrates the issues around the use of economic n-of-1 trials with a hypothetical example, and discusses their potential for the estimation of individualized cost-effectiveness.

Thiamine for Alzheimer's disease

BACKGROUND

Vitamin B1 (thiamine) plays an important role in Wernicke-Korsakoff syndrome (a form of amnesia caused by brain damage occurring in long-term alcoholics who rely mainly on alcohol for nutrition). The acute syndrome is normally reversible but may proceed to profound dementia, although its progress can be stopped by a timely injection of a large dose of thiamine. There have been suggestions that thiamine may have a beneficial effect in Alzheimer's disease.

OBJECTIVES

The objective of this systematic review is to evaluate evidence of the effect of thiamine for Alzheimer's disease.

SEARCH STRATEGY

The Cochrane Controlled Trials Register and the CDCIG Register were searched using the terms 'thiamine*, alzheimer* and vitamin* B1'. Other sources were also searched.

SELECTION CRITERIA

All unconfounded, double-blind, randomized trials in which treatment with thiamine was administered for more than a day and compared to placebo in patients with dementia of the Alzheimer's type.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers, pooled if appropriate and possible, and the pooled odds ratios (95% CI) or the average differences (95% CI) were estimated. No intention-to-treat data were available to be used.

MAIN RESULTS

Few data were available for review. The data were compatible with thiamine producing harm, no change or improvement. For measures of cognition, the effect of thiamine was non-significantly worse than placebo on the Mini Mental State Examination score (0-30; high=good) at 12 months: WMD -4.3 (95% CI: -14.4 - +5.8) and at time points 3, 6 and 9 months. Change from baseline analyses showed placebo to be significantly better than thiamine at all time points beyond three months; WMD -4.8 (95% CI: -6.0 to -3.6) at 12 months. There was no statistically significant difference in the test of Verbal Fluency and the Boston Naming Test. These analyses were based only on those who completed the study and not on intention-to-treat analyses. There were no results presented for withdrawal by treatment group. Data on measures of functional autonomy, behaviour, quality of life, dependency, or effect on carer were not available.

REVIEWER'S CONCLUSIONS

This review finds no evidence that thiamine is a useful treatment for the symptoms of Alzheimer's disease. The data are so poor and sparse that it is difficult to state almost anything of its effect in Alzheimer's disease. Thiamine cannot be recommended for patients with Alzheimer's disease.

Tacrine for Alzheimer's disease

BACKGROUND

Tacrine is one of the first drugs to be widely marketed for the loss of memory and intellectual decline in Alzheimer's disease. The alleged success of tacrine in the treatment of these symptoms has been heralded as confirmation of the cholinergic theory of Alzheimer's disease. However, the efficacy of tacrine for symptoms of dementia remains controversial. This is reflected by the low rate of prescription of tacrine in countries where it is approved and the lack of approval by several regulatory authorities in Europe and elsewhere. The uncertainty about the efficacy of tacrine is due to the difficulties in interpretation of the results from the clinical trials. The reasons for this are the small effects of tacrine compared to placebo for all outcomes; the high incidence of adverse events; the lack of benefit observed in several trials; the use of cross-over designs and their associated methodological problems in a disease like dementia; the use of different measurement scales to assess outcome in different trials; and the problem of high dropout rates.

OBJECTIVES

To determine the clinical efficacy of tacrine for the symptoms of Alzheimer's disease.

SEARCH STRATEGY

The Cochrane Dementia Group Register of Clinical Trials was searched using the terms 'tacrine', 'tetrahydroaminoacridine' and 'THA' (see the Group's search strategy for full details).

SELECTION CRITERIA

All unconfounded, double-blind, randomized trials in which treatment with tacrine was administered for more than a day and compared to placebo in patients with dementia of the Alzheimer's type.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers, pooled if appropriate and possible, and the pooled odds ratios (95%CI) or the average differences (95%CI) were estimated. Where possible, intention-to-treat data were used.

MAIN RESULTS

This review produced no clear results. The results were compatible with tacrine producing improvement, no change or even harm for those with Alzheimer's disease. It was not possible to use many of the published results in a combined analysis. For measures of overall clinical improvement, the intention-to-treat analyses failed to detect any difference between tacrine and placebo (OR 0.87; 95%CI 0.61 - 1.23). Behavioural disturbance, as measured by the Alzheimer's Disease Assessment Scale-noncognitive, failed to detect any difference between tacrine and placebo (SMD -0.04; 95%CI -0.52 - 0.43). For cognition function, the effect of tacrine was not statistically significantly different from placebo for the MiniMental State Examination score (0-30; high =good) (SMD 0.14; 95%CI -0.02 - 0.30) and was barely statistically significantly in favour of treatment for the Alzheimer's Disease Assessment Scale-cognitive scale (SMD -0.22; 95%CI -0.32 - -0.13). Adverse events were not reported in a systematic way in the different trials, making formal comparison difficult. Raised serum liver enzymes was the major reason for withdrawal. The odds ratio for withdrawal due to an adverse event was significantly different from one, the control group experienced fewer events (OR 5.7; 95%CI 4.1-7.9). Gastrointestinal side effects (diarrhoea, anorexia, dyspepsia and abdominal pain) were the other major cause of adverse events and for withdrawal, and the odds ratio for withdrawal was also significantly different from one in favour of the control group (OR 3.8; 95%CI 2.8-5.1). No deaths were reported in any of the studies during the trial period, up to six months.

REVIEWER'S CONCLUSIONS

This review provides no convincing evidence that tacrine is a useful treatment for the symptoms of Alzheimer's disease. However, as so few trials presented data in a format suitable for pooling, the results of this review may be modified when further data from all relevant trials are included. There is an urgent need for the independent evaluation of the data already existing in the trials but not accessible through published or grouped data. A

Cholinesterase inhibition for Alzheimer disease: a meta-analysis of the tacrine trials. Dementia Trialists' Collaboration

OBJECTIVES

To determine the effects of cholinesterase inhibition with tacrine hydrochloride for the symptoms of Alzheimer disease in terms of cognitive performance, clinical global impression, behavior, and functional autonomy.

DATA SOURCES

The Cochrane Dementia Group registry of trials.

STUDY SELECTION

Unconfounded, randomized, double-blind, placebo-controlled trials in which tacrine had been given for more than 1 day and that were completed before January 1, 1996.

DATA EXTRACTION

Two reviewers independently selected trials for inclusion and individual patient data were sought.

DATA SYNTHESIS

Data were analyzed from 12 trials that included 1984 patients with Alzheimer disease. At 12 weeks, cognitive performance, as measured by the Mini-Mental State Examination (score range, 0-30), was better in patients receiving tacrine than in patients receiving placebo by 0.62 points (95% confidence interval [CI], 0.23-1.00; P=.002). Compared with similar untreated patients who would be expected to deteriorate by 0.50 to 1.00 points on the Mini-Mental State Examination during 12 weeks, the progress of patients receiving tacrine would be expected to range between an improvement of 0.12 and a deterioration of 0.38 points. The odds ratio for improvement on the Clinical Global Impression of Change scale (range, 1-7) for patients receiving tacrine compared with those receiving placebo was 1.58 (95% CI, 1.18-2.11; P=.002). The behavioral noncognitive subscale of the Alzheimer's Disease Assessment Scale (range, 0-50) showed a difference in favor of tacrine of 0.58 points (95% CI, 0.17-1.00; P= .006). Improvement on the Progressive Deterioration Scale, largely an index of functional activities, was not significant (0.75; 95% CI, -0.43 to 1.93; P=.21). Age, severity of dementia, and exposure to tacrine prior to randomization had no clear influence on the treatment effect. There was a nonsignificant trend toward increasing effect with increasing dose for cognitive function and the Clinical Global Impression of Change. For patients without prior exposure to tacrine, the odds of patients' withdrawing during the study while they were receiving tacrine compared with placebo was 3.63 (95% CI, 2.80- 4.71; P<.001). Eleven (95% CI, 7-31) patients would need to be treated to achieve any improvement on the Clinical Global Impression scale, and 42 (95% CI, 23-125) to achieve a moderate or marked improvement. One patient would be expected to withdraw for every 4 (95% CI, 3-5) patients treated.

CONCLUSIONS

Cholinesterase inhibition with tacrine appears to reduce deterioration in cognitive performance during the first 3 months and increase the odds of global clinical improvement. Effects observed on measures of behavioral disturbance were of questionable clinical significance, and functional autonomy was not significantly affected. The clinical relevance of the benefits of cholinesterase inhibition remains controversial, and long-term trials with clinically relevant end points are required.

Are risk factors for stroke and coronary disease the same?

Many risk factors operate in both coronary heart disease and stroke, especially ischaemic stroke--age, sex, social class, blood pressure, pre-existing vascular disease (angina, myocardial infarction, cardiac failure, diabetes and peripheral vascular disease, transient ischaemic attack and stroke), atrial fibrillation and fibrinogen, smoking, alcohol and height. Total cholesterol has also recently been recruited to this list. The various mechanisms involved in stroke and its subtypes and the epidemiological problems in evaluating aetiological factors in stroke make the comparison with coronary heart disease more difficult. The recent discrepancy between much of the epidemiology and the clinical trials evaluating the role of lipids in stroke has spurred the systematic review (meta-analysis) of major prospective observational studies. These will provide a clearer assessment about the quantitative comparison of some of the more important risk factors for stroke and coronary heart disease in the near future.

Von Willebrand factor and risk of ischemic stroke

We carried out a case-control study to determine whether von Willebrand factor (vWF) antigen (and factor VII and tissue plasminogen activator [tPA] antigens) are associated with ischemic stroke. Ninety-five patients with transient ischemic attack or minor ischemic stroke recruited from the Oxfordshire Community Stroke Project and one neurology clinic were compared with 236 controls, group-matched for age and sex, from the same general practitioners as the incident cases. In crude analyses, concentrations of vWF antigen were significantly higher in cases than in controls (p = 0.004). The age- and sex-adjusted odds ratios from lowest (referent) to highest quartile of vWF antigen were 1.00, 1.15, 2.34, and 2.36 (trend test, p = 0.006). Factor VII antigen and tPA antigen were not significantly different between cases and controls. Although adjustment for other potential risk factors abolished the statistical significance of the association between vWF and disease, this was largely due to the influence of history of ischemic heart disease. We conclude that vWF is a potent and independent risk factor for transient ischemic attack, minor ischemic stroke, and, by extrapolation, ischemic stroke in general. The data also suggest that vWF may be a risk factor for both ischemic stroke and ischemic heart disease. We found no evidence to implicate factor VII and tPA as risk factors for ischemic stroke.