The impact of research quality and study design on epidemiologic estimates of the effect of nonsteroidal anti-inflammatory drugs on upper gastrointestinal tract disease

Management of gout in the older adult

BACKGROUND

Gout affects 3 million people in the United States, with rates almost 5 times higher in those aged 70 to 79 years compared with those aged < 50 years. Management of gout in elderly subjects can be complicated by comorbidities and polypharmacy.

OBJECTIVE

The purpose of this article was to review the unique clinical presentation, treatment, and prevention of gout in the older adult, with attention to the age-related factors that may affect outcomes in this population.

METHODS

PubMed and the Iowa Drug Information Service were searched (1944-January 14, 2011) for clinical studies of gout using the following search terms: gout, elderly, colchicine, non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroid, prednisone, prednisolone, methylprednisolone, triamcinolone, allopurinol, febuxostat, probenecid, sulfinpyrazone, uricosuric, fenofibrate, and losartan. Articles were limited to clinical trials in humans, published in English. Citations of these articles were analyzed for additional relevant studies, and current guidelines were also consulted.

RESULTS

Twenty-nine citations were reviewed. Evidence suggests that colchicine, NSAIDs, and corticosteroids are all efficacious in the treatment of acute gout in the older adult. Relevant limitations to colchicine use in the older adult include high cost, dosing restrictions in severe renal and hepatic dysfunction, gastrointestinal intolerance, and potential drug interactions. NSAID therapy is not recommended in older patients with congestive heart failure, renal failure, or gastrointestinal problems. Corticosteroids pose little risk when used in the short-term and may be preferred in patients with contraindications to colchicine or NSAIDs. Urate lowering with allopurinol for prevention of gout is well tolerated and has minimal cost per month; however, dose reduction is recommended in patients with renal impairment, which often results in failure to achieve target serum urate concentrations. Febuxostat does not require dose adjustment in mild to moderate renal disease and may be preferred in older people with this condition.

CONCLUSION

Management of gout in the older adult involves careful selection of treatment based on potential benefits and consequences of therapy, considered in tandem with individual patient-specific characteristics. ClinicalTrials.gov identifiers NCT00549549, NCT01101035, NCT00241839, NCT01157936, NCT00997542, NCT00288158, and NCT00987415.

Gastrointestinal-Related Complications in a Long-Term Care Population Taking NSAIDs Versus COX-2 Inhibitor Therapy

OBJECTIVES

To determine the following in a long-term care population taking traditional nonsteroidal anti-inflammatory drug (NSAID) or cyclo-oxygenase-2 (COX-2) inhibitor therapy: (1) incidence of gastrointestinal (GI) adverse events and GI-related hospitalizations, (2) prevalence of GI-protective medication use, and (3) prevalence of GI risk factors as defined by Indiana Medicaid prior-authorization criteria.

DESIGN

Longitudinal cross-sectional study.

SETTING

Long-term care facilities in Indiana.

PATIENTS

Residents in long-term care and assisted-living facilities were included if they were receiving either traditional NSAID or COX-2 inhibitor therapy.

MAIN OUTCOME MEASURES

The number of residents experiencing GI intolerance or complications or GI-related hospitalizations associated with NSAID or COX-2 inhibitor use.

RESULTS

Over this 14-month evaluation period, 1,198 long-term care and assisted living residents were identified as receiving NSAID or COX-2 inhibitor therapy. Celecoxib was the most frequently prescribed medication used in this population. Age >70 years and concomitant aspirin use were the most frequently noted risk factors for GI disease. Significantly fewer GI complications were observed in COX-2 recipients (4.0%) compared with NSAID users (8.4%) (P = 0.002). GI-related hospitalizations occurred significantly less with COX-2 use (2.0%) compared with traditional NSAID use (4.5%) (P = 0.014). A relatively low incidence of GI-related events also was associated with ibuprofen use.

CONCLUSION

Individuals residing in assisted living or long-term care settings had lower rates of GI complications and hospitalizations related to COX-2 inhibitors compared with traditional NSAIDs.

Non-steroidal anti-inflammatory drugs and the enteropathy

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most widely used anti-inflammatory agents in clinic. Recently, they are also used to prevent the progression of cardiovascular disease and the pain of muscle, bone and arthrosis. However, long-term and generous use may cause mucosal damages of the stomach and duodenum. With the improvement of clinical diagnostic and therapeutic approaches, it has been found that more and more damages of the intestinal mucosa were being identified. This article reviews the enteropathy caused by NSAIDs and its pathogenic mechanism, prevention and treatment.

Preventive effects of rebamipide on NSAID-induced gastric mucosal injury and reduction of gastric mucosal blood flow in healthy volunteers

The precise mechanisms of acute damage and the role of gastric mucosal blood flow in gastric mucosal injury induced by nonsteroidal anti-inflammatory drugs (NSAIDs) remain uncertain. The aim of this study was to evaluate the preventive effect of rebamipide on gastric mucosal injury and reduction of gastric mucosal blood flow (GMBF) after ibuprofen administration. Twenty healthy volunteers were randomized two groups. The rebamipide group took ibuprofen, 1800 mg/day, and rebamipide, 100 mg t.i.d., for 7 days. The placebo group took ibuprofen, 1800 mg/day. The numbers of gastric ulcer subjects were three in the placebo group and zero in the rebamipide group. The mean modified Lanza score after ibuprofen administration was significantly higher in the placebo group than the rebamipide group (2.9+/-1.7 vs. 1.3+/-1.0, respectively; P=0.032). The GMBF of the placebo group was significantly decreased at antrum from baseline, from 2.8+/-0.5 to 2.0+/-0.5 tissue perfusion units (P=0.005). There was no difference in GMBF change in the rebamipide group. Gastric mucosal injury was correlated with GMBF reduction in antrum (r=-0.677, P=0.001). In conclusion, it is suggested that the decrease in GMBF may have been associated with NSAID-induced gastric mucosal injury, and rebamipide may have prevented NSIAD-induced gastric mucosal injury by maintaining GMBF in healthy subjects.

Gastrointestinal safety of cyclooxygenase-2 inhibitors: a Cochrane Collaboration systematic review

BACKGROUND & AIMS

Nonselective non-steroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase-2 inhibitors (COX-2s) are used to treat a variety of arthritic and inflammatory conditions. The aim of this study was to assess the upper gastrointestinal (GI) harms of the long-term use of COX-2s, compared with nonselective NSAIDs and placebo, in arthritis sufferers.

METHODS

A systematic review of randomized controlled trials (RCTs) was conducted. Searches were conducted in (1) Cochrane Central Register of Controlled Trials (CENTRAL), (2) the Cochrane Collaboration Library (2005), (3) MEDLINE (to December 2006), and (4) Excerpta Medica Database (EMBASE) (to June 2005). Reference lists from trials and abstracts of conference proceedings were searched by hand, and experts were contacted to identify further relevant trials. RCTs of celecoxib, rofecoxib, etoricoxib, valdecoxib, and lumiracoxib were included if they reported on endoscopic ulcers, clinically important ulcer complications, or adverse gastrointestinal (GI) symptoms with the use of these COX-2s, compared with placebo or with nonselective NSAIDs. Study selection and data extraction were performed in duplicate by independent reviewers. Data were analyzed by using Review Manager 4.2 in accordance with accepted meta-analysis techniques.

RESULTS

Compared with nonselective NSAIDs, COX-2s produced significantly fewer gastroduodenal ulcers (relative risk, 0.26; 95% confidence interval, 0.23-0.30) and clinically important ulcer complications (relative risk, 0.39; 95% confidence interval, 0.31-0.50), as well as fewer treatment withdrawals caused by GI symptoms. The co-administration of acetylsalicylic acid appears to reduce the GI safety of COX-2s in subgroup analyses.

CONCLUSIONS

COX-2s appear to offer greater upper GI safety and are better tolerated than nonselective NSAIDs. The co-administration of acetylsalicylic acid might reduce the safety advantage of COX-2s over that of nonselective NSAIDs.

Risk of upper gastrointestinal complications among users of traditional NSAIDs and COXIBs in the general population

BACKGROUND & AIMS

Traditional nonaspirin, nonsteroidal anti-inflammatory drugs (tNSAIDs) have been associated with a 3- to 5-fold increased risk in upper gastrointestinal complications (UGIC). Whether use of selective inhibitors of cyclooxygenase-2 (COXIBs) will translate into a clinically relevant reduced toxicity has not been widely investigated in the general population.

METHODS

We conducted a nested case control study using The Health Improvement Network Database identifying 1561 cases of UGIC between January 2000 and 2005. A random sample of 10,000 controls was frequency matched to the cases by age, sex, and calendar year.

RESULTS

The adjusted relative risk (RR) of UGIC associated with current use was 3.7 (95% CI: 3.1-4.3) for tNSAIDs and 2.6 (95% CI: 1.9-3.6) for COXIBs. Daily dose was a predictor of increased risk for both tNSAIDs and COXIBs. Users of tNSAIDs with a prolonged plasma half-life or slow release formulations had an augmented risk of UGIC. Overall, the estimate of RR associated with COXIBs was 0.8 (95% CI: 0.6-1.1) compared with current use of tNSAIDs, and, among nonusers of aspirin, the corresponding estimate of RR associated with COXIBs was 0.6 (95% CI: 0.4-0.9).

CONCLUSIONS

COXIBs present a better upper gastrointestinal safety than tNSAIDs, although the risk of UGIC for an individual drug is determined by its daily dose and plasma drug exposure in addition to its selectivity for cyclooxygenase-2. Also, concomitant use of aspirin is a strong effect modifier of COXIBs that negates the superior gastrointestinal safety over tNSAIDs in the absence of aspirin use.

Upper gastrointestinal complications among users of paracetamol

Non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with upper gastrointestinal complications such as bleeding or perforation. Paracetamol has been traditionally considered a safer alternative to NSAIDs. In a previous case-control study we found that paracetamol at high doses increased the risk of upper gastrointestinal complications. We proposed to review all studies addressing the association between paracetamol and upper gastrointestinal complications and placed our results in the context of existing literature. We conducted a nested case-control study using the United Kingdom General Practice Research Database during the period between April 1993 and October 1998. Then we performed a systematic review of the literature indexed in MEDLINE published between 1980 and 2004. We identified a total of twelve studies that assessed the association between paracetamol and upper gastrointestinal complications. We used a fixed effects model to calculate a summary estimate of these studies. In the nested case control study, use of paracetamol was associated with a small elevated risk of upper gastrointestinal complications (relative risk (RR), 1.3; 95% confidence interval (CI), 1.1-1.5). The RR was 3.6 (95% CI, 2.6-5.1) among paracetamol users of more than 2 g daily, whereas smaller doses did not increase the risk. Among the twelve studies identified in the systematic review, estimates ranged from 0.2 through 2.0 with a summary estimate of 1.3 (95% CI, 1.2-1.5). Our findings indicate that use of paracetamol at the doses most commonly used confer little or no increased risk of upper gastrointestinal complications. More data are needed to confirm or refute the suggestion that high-dose paracetamol is associated with an increased risk of upper gastrointestinal complications of the same magnitude as the one observed with traditional NSAIDs.

Pharmacoepidemiology and rheumatic disorders

This article reviews the application of pharmacoepidemiology in the evaluation of drugs that are used commonly for rheumatic disorders. Data sources and methodology considerations for these studies are highlighted. The topics that are covered included the safety evaluation of nonsteroidal ant-inflammatory drugs, adverse pregnancy outcomes of pharmaceutical agents, gastroduodenal safety of alendronate, long-term beneficial effects of methotrexate for rheumatoid arthritis, and drug use study.

Nitric oxide and cyclooxygenase may participate in the analgesic and anti-inflammatory effect of the cucurbitacins fraction from Wilbrandia ebracteata

Wilbrandia ebracteata is a medicinal plant from South America used in folk medicine for the treatment of chronic rheumatic diseases. We have shown that the high performance liquid chromatography-characterized (HPLC) dichloromethane fraction isolated from Wilbrandia ebracteata (WEDC) inhibits the parameters observed in experimental models of inflammation in vivo and in vitro. In the present study, we extend our previous observations on the analgesic effects of WEDC by investigating its actions using the hot plate test and zymosan-induced writhing test in mice, as well as zymosan-induced arthritis in rats evaluating articular inflammatory pain, cell migration and determination of NO release into the joint exudate. The effect of WEDC on the activity of COX-1 and COX-2 in vitro and its ulcerogenic capacity in vivo were also investigated. The oral treatment of the animals with WEDC (1-10 mg/kg) produced a significant, dose-dependent reduction of articular incapacitation and abdominal contortions in the writhing test. The same effect was not observed in the hot plate and rota-rod tests. WEDC also reduced nitrite release into the zymosan-inflamed joints. In the evaluation of COX activity, we observed that WEDC was able to selectively inhibit COX-2 but not COX-1 activity in COS-7 cells. Moreover, WEDC treatment did not show gastrointestinal toxicity. Our data confirm the anti-nociceptive activities of the WEDC and indicate that this effect could be associated with inhibition of cyclooxygenase-2 (COX-2) and nitric oxide release. The effects could be attributed to cucurbitacins since several of these were isolated from the WEDC.

Endoscopic evidence of mucosal injury in patients taking ticlopidine compared with patients taking aspirin/nonsteroidal antiinflammatory drugs and controls

BACKGROUND

Ticlopidine is a novel antiplatelet agent used alone or in combination with aspirin and anticoagulants in the treatment and prevention of various vascular diseases. Gastrointestinal side effects, including bleeding, have been reported with use of ticlopidine in most of the vascular prevention trials. We studied the endoscopic evidence of mucosal damage in patients taking ticlopidine compared with patients taking aspirin/nonsteroidal antiinflammatory drugs (NSAIDs) and matched controls.

STUDY

We performed a longitudinal review of gastrointestinal endoscopy, pharmacy databases, and medical records of patients referred to our service over a period of 6 months for endoscopic evaluation of upper gastrointestinal bleeding, unexplained anemia, or abdominal pain. Data were collected and analyzed for 55 patients taking ticlopidine, 77 age- and gender-matched patients taking aspirin or NSAIDs, and 560 age- and gender-matched control patients not taking any of these medications.

RESULTS

The overall prevalence of ulcers was marginally higher in the aspirin/NSAID group than in the ticlopidine group (35% vs. 29%) and was significantly higher among patients taking aspirin, NSAIDs, or ticlopidine than among controls (15%). Gastritis was also noted more frequently in the aspirin/NSAID and ticlopidine groups than in the control group. Endoscopic evidence of esophagitis was significantly more frequent in the control group than in the aspirin/NSAID and ticlopidine groups. There was no significant difference across groups in the prevalence of ulcers, gastritis, or esophagitis.

CONCLUSIONS

Patients taking ticlopidine are more likely to have endoscopic evidence of mucosal damage than matched control patients and are nearly as likely to have such damage as endoscopically evaluated patients taking aspirin or NSAIDs. However, these findings must be confirmed using prospective cohort data for patients in primary care settings, to avoid referral bias.

Gastrointestinal toxicity associated with nonsteroidal anti-inflammatory drugs. Epidemiologic and economic issues

The large body of literature on the gastrointestinal side effects of NSAIDs has shown consistently that populations can be identified that have a markedly elevated risk for these iatrogenic conditions. These groups include the elderly, persons with prior history of peptic ulcer disease and its complications, persons receiving anticoagulant and corticosteroid therapy, and persons who require long-term NSAID therapy, especially at high dose. It is possible that several comorbidities (e.g., rheumatoid arthritis) predispose patients to gastrointestinal complications caused by NSAIDs, but few studies have adjusted carefully for the possibility that concomitant medication use (e.g., oral anticoagulants, corticosteroids) or increased NSAID dose may account best for apparent association of comorbidities as a risk factor for serious gastrointestinal events. The role of H. pylori infection in affecting the risk of complicated ulcer disease among NSAID users remains to be fully elucidated. Low-dose aspirin for cardioprotective use is associated with an increased risk for PUBs; when used concomitantly with NSAIDs, this increases the risk of PUBs above that of the NSAID itself. Apart from the physical toll NSAID-related gastrotoxicity places on the patient, there are considerable economic consequences to patients, providers, and society. This cost presents a subject for research for those interested not only in improving the quality of patient care, but also in the prudent use of health care resources.

Low levels of gastric mucosal glutathione during upper gastric bleeding associated with the use of nonsteroidal anti-inflammatory drugs

OBJECTIVES

To investigate the glutathione concentrations in gastric mucosa from patients with acute gastric bleeding related to nonsteroidal anti-inflammatory drugs (NSAIDs), and to test the influence of nutritional status on mucosal glutathione. Glutathione protects the gastrointestinal mucosa against reactive oxygen species, and glutathione content in various tissues may be depleted during malnutrition.

METHODS

Endoscopic biopsies were obtained from 39 patients. Eighteen of these (9 well-nourished, 9 malnourished) presented with gastric bleeding ulcers related to NSAIDs. Twenty-one other patients (12 well-nourished, 9 malnourished) underwent normal routine diagnostic endoscopy and served as controls. Malnutrition was defined as a loss of over 10% of normal body weight and/or plasma albumin levels below 30 g/l. Gastric biopsies were taken from the fundus and antrum (controls) and from the region of the ulcer (patients with acute bleeding) and frozen quickly until glutathione analysis by high-performance liquid chromatography (HPLC) coulometric detection. Results were expressed as nmol/mg wet tissue.

RESULTS

Gastric mucosal glutathione levels were significantly (P < 0.05) lower in both the antrum (0.81 +/- 0.34 v. 1.41 +/- 0.88 nmol/mg tissue) and the fundus (1.04 +/- 0.54 v. 1.43 +/- 0.92 nmol/mg tissue, P < 0.05) in malnourished than in well-nourished control patients. Glutathione mucosal concentrations were decreased significantly in patients with NSAID-induced gastric bleeding compared with control patients (0.38 +/- 0.36 v. 1.12 +/- 0.56 nmol/mg tissue, P < 0.001), and the lowest glutathione levels were observed in malnourished patients (0.28 +/- 0.20 v. 0.48 +/- 0.15 nmol/mg tissue in well-nourished patients, not significant).

CONCLUSION

Malnutrition is associated with low levels of gastric glutathione. This may contribute to the severity and the onset of haemorrhage in NSAID-induced gastric ulcers.

Relative risk of upper gastrointestinal complications among users of acetaminophen and nonsteroidal anti-inflammatory drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been associated with an increase in upper gastrointestinal complications. There is no agreement, however, on whether all conventional NSAIDs have a similar relative risk (RR), and epidemiologic data are limited on acetaminophen. We studied the association between these medications and the risk of upper gastrointestinal bleed/perforation in a population-based cohort of 958,397 persons in the United Kingdom between 1993 and 1998. Our nested case-control analysis included 2,105 cases and 11,500 controls. RR estimates were adjusted for several factors known to be associated with upper gastrointestinal bleed/perforation. Compared with non-users, users of acetaminophen at doses less than 2 gm did not have an increased risk of upper gastrointestinal complications. The adjusted RR for acetaminophen at doses greater than 2 gm was 3.6 [95% confidence interval (95% CI) = 2.6-5.1]. The corresponding RRs for low/medium and high doses of NSAIDs were 2.4 (95% CI = 1.9-3.1) and 4.9 (95% CI = 4.1-5.8). The RR was 3.1 (95% CI = 2.5, 3.8) for short plasma half-life, 4.5 (95% CI = 3.5-5.9) for long half-life, and 5.4 (95% CI = 4.0-7.1) for slow-release formulations of NSAIDs. After adjusting for daily dose, the differences in RR between individual NSAIDs tended to diminish except for apazone. Users of H2 receptor antagonists, omeprazole, and misoprostol had RRs of 1.4 (95% CI = 1.2-1.8), 0.6 (95% CI = 0.4-0.9), and 0.6 (95% CI = 0.4-1.0), respectively. Among NSAID users, use of nitrates was associated with an RR of 0.6 (95% CI = 0.4-1.0).

Reliability of Chalmers' scale to assess quality in meta-analyses on pharmacological treatments for osteoporosis

PURPOSE

This study estimates the inter-rater and test-retest reliability of Chalmers' quality score scale in the context of bone mass loss and fracture rate in postmenopausal women.

METHODS

An exhaustive literature search was performed on Medline to locate clinical trials studying the effect of medication use on bone mass loss and fracture rate in postmenopausal women. Twenty articles were randomly selected and four raters independently assessed the quality of each article with Chalmers' scale. Among the 20 articles, 10 were blinded on authors' names, journal, year of publication and source of funding. Raters were also asked to assess all 20 articles one more time, two months after the first evaluation. Intraclass (ICC) and test-retest correlation coefficients were calculated.

RESULTS

The overall inter-rater ICC was 0.66 [0.55, 0.79](95%). The overall test-retest reliability of Chalmers' scale was 0.81 [0.67, 0. 98](95%). When ratings were stratified according to articles' blinding status, blinded assessments generated a smaller inter-rater ICC than non-blinded assessments: 0.30 [0.17, 0.53](95%) vs. 0.80 [0. 71, 0.90](95%). In addition, analyzing sub-scales separately generated different estimates of reliability.

CONCLUSIONS

This study shows that the reliability of the quality scale developed by Chalmers substantially varies between sub-scales, and is highly dependent on articles' blinding status. The possibility of bias in rating non-blinded articles can not be ruled out. The reliability of the scale can also be dependent on the outcome studied.

Over-the-counter analgesics and antipyretics: a critical assessment

BACKGROUND

It is just 100 years since the introduction of aspirin to medicine. Since then, aspirin and its derivatives have been joined by acetaminophen, and the nonsteroidal anti-inflammatory drugs--ibuprofen, naproxen sodium, and ketoprofen--as the only over-the-counter (OTC) agents approved by the US Food and Drug Administration for the short-term treatment of pain, headache, dysmenorrhea, and fever. Recently the prescription use of aspirin has expanded to include a number of antiplatelet indications.

OBJECTIVE

The purpose of this paper is to review critically the history, mechanisms of action, efficacy, and tolerability of OTC analgesic and antipyretic products. Relatively new and potential future indications for these drugs are also discussed.

CONCLUSION

Although all of the OTC analgesic/antipyretic agents seem to share a common mechanism of prostaglandin inhibition, there are important differences in their pharmacology, efficacy, and side-effect profiles. Considering their often-unsupervised use, the risk-benefit ratio of this class of drugs has been extremely favorable. However, when used inappropriately, even these drugs pose significant risks to certain patient populations.

Comparative safety evaluation of non-narcotic analgesics

Both spontaneous reports and single outcome studies may distort the overall safety evaluation of drugs. We identified epidemiologic studies, published from January 1970 to December 1995, that investigated the association of serious adverse effects with aspirin, diclofenac, acetaminophen, and dipyrone to determine and compare the excess mortality associated with short-term drug use. The estimated excess mortality due to community-acquired agranulocytosis, aplastic anemia, anaphylaxis, and serious upper gastrointestinal complications was 185 per 100 million for aspirin, 592 per 100 million for diclofenac, 20 per 100 million for acetaminophen, and 25 per 100 million for dipyrone. The estimates were largely influenced by the excess mortality associated with upper gastrointestinal complications. A relative risk estimate of 300 or more for the association of dipyrone with agranulocytosis would have been necessary for the excess mortality of dipyrone to be comparable to that of aspirin or diclofenac. Based on published epidemiologic evidence used to determine the excess mortality associated with short-term use of these four non-narcotic analgesics, the current regulatory ranking of the drugs appears inappropriate.

Combining studies using effect sizes and quality scores: application to bone loss in postmenopausal women

This article presents a random effects model that uses effect sizes (ES) and quality scores to integrate results from investigations. An empirical example is given with data obtained from a meta-analysis on the effectiveness of physical activity in the prevention of bone loss in healthy postmenopausal women. A Medline search was performed to locate relevant studies published in French or English between January 1966 and May 1996. Three independent reviewers extracted data from studies. Effect sizes were calculated according to the method of Hedges and Olkin. A modified version of Chalmers' scale was utilized to calculate quality scores. DerSimonian and Laird's method with incorporation of the quality scores was used to estimate the overall effect size. Quality scores and the inverse of the variances were included as weights when combining studies. The overall estimate and standard error (SE) of the effect of physical activity on spinal bone mineral density loss in healthy postmenopausal women was ESoverall = 0.4263 (1.1361). When compared to other meta-analysis methods such as the fixed effects model and the model of DerSimonian and Laird without the quality score (DL), the new model generated comparable estimators (fixed effects model's ESoverall (SE) = 1.2724 (0.0139), DLs ESoverall (SE) = 0.3958 (1.2370)). Due to the heterogeneity that existed between studies, a random effects model was more appropriate then a fixed effects model. However, it resulted in wider confidence intervals, as expected. It was shown empirically that the model using quality scores generated narrower confidence intervals than the model of DL alone. The inclusion of covariates such as quality scores in meta-analyses permits the quantification of the variation between studies.

A cohort study (with re-sampled comparator groups) to measure the association between new NSAID prescribing and upper gastrointestinal hemorrhage and perforation

This cohort study examined the relationship between newly prescribed NSAIDs (none in the previous six months) and upper gastrointestinal hemorrhage and perforation in Tayside, Scotland. Exposure was classified by prescription duration. The study population consisted of the population of Tayside. A Comparator Group was chosen at random (within age and sex strata). Two hundred re-sampled comparator groups were created. Statistical analyses were carried out by Poisson regression (repeated for each of the re-samples). The analyses controlled for age, sex, prior hospitalization for upper gastrointestinal events, prior endoscopy, and the use of ulcer healing drugs. There were 78,191 subjects in the NSAID group, and 78,207 in each of the comparator groups. The increased risk with NSAIDs was only apparent for subjects without a history of upper gastrointestinal events; univariate rate ratio = 2.76 (1.90, 4.01). The final, re-sampled estimate of NSAID risk was rate ratio = 2.48 (1.87, 3.29).

Meta-analysis of risk factors for peptic ulcer. Nonsteroidal antiinflammatory drugs, Helicobacter pylori, and smoking

Attributable risk models describe the role of three risk factors for peptic ulcer and related serious upper gastrointestinal (GI) events. The factors-nonsteroidal antiinflammatory drugs (NSAIDs), Helicobacter pylori, and cigarette smoking-have been identified as major risk factors for peptic ulcer in numerous clinical and epidemiologic studies. Overall risk ratios for each risk factor were based on meta-analyses of English-language studies of risk for peptic ulcer-related GI events. Exposure estimates for factors used data from North American populations. Summary risk and exposure values were computed for the general population, males and females separately, and the elderly. Hypothetical models of multiple factor attributable risks were developed using population attributable risk percent calculated from these summary values. General population attributable risk percent were as follows: 24%, NSAIDs; 48%, H. pylori; and 23%, cigarette smoking. Based on these numbers, the "no interaction" attributable risk model estimates that 95% of total peptic ulcer related risk is attributable to these factors in the general population. The "interaction" model attributes 89% of cases to these risk factors: 24%, NSAIDs alone; 31%, H. pylori alone; 34%, H. pylori/smoking combined. Between 89% and 95% of peptic ulcer-related serious upper GI events may be attributed to NSAID use, H. pylori infection, and cigarette smoking.

Are non-pharmacological nursing interventions for the management of pain effective?--A meta-analysis

A meta-analysis of randomized controlled trials (RCTs) assessing the effectiveness of a non-pharmacological intervention on the management of pain was conducted. Forty-nine relevant primary studies were identified and retrieved. Individual mean pain scores from these studies were converted to standardized effect sizes and meta-analyses were conducted. Although there is evidence, in the form of primary studies, to suggest that non-pharmacological nursing interventions are effective in the management of pain, the 49 studies, pooled in this meta-analysis, were too heterogeneous to detect a difference between the treatment and control groups reliably. There is a need to rigorously test these interventions in the form of primary RCTs.

The risks and costs of upper gastrointestinal disease attributable to NSAIDs

NSAIDs, including both aspirin and nonaspirin NSAIDs, are among the most frequently used drugs, and their use may result in serious adverse gastrointestinal outcomes and significant medical costs. The increased risks for adverse upper GI hemorrhage and peptic ulcer disease associated with NSAID use have been demonstrated in observational studies and clinical trials; an overview of these results is presented in this article. The magnitude of these risks should play an important role in clinical decision making and should influence decisions regarding the use of this class of drugs.

Meta-analyses to evaluate analgesic interventions: a systematic qualitative review of their methodology

A systematic search of the literature was performed to identify the maximum possible number of meta-analyses that evaluated analgesic interventions. Seventy-four reports were identified and retrieved and the scientific quality of 80 separate meta-analyses was assessed under blind conditions by 2 judges using Oxman and Guyatt's index. Most of the meta-analyses evaluated pharmacological interventions for chronic pain conditions and two-thirds were published since 1990. Ninety percent of the meta-analyses had methodological flaws that could limit their validity. The main deficiencies were lack of information on methods to retrieve and to assess the validity of primary studies and lack of data on the design of the primary studies. Meta-analyses of low quality produced significantly more positive conclusions. For several topics, different meta-analyses evaluating the same intervention produced conflicting results. The need to resolve these contradictions is highlighted.