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Chris Del Mar

Bio: Chris Del Mar is an academic researcher from Bond University. The author has contributed to research in topics: Randomized controlled trial & Health care. The author has an hindex of 64, co-authored 354 publications receiving 14798 citations. Previous affiliations of Chris Del Mar include University of Queensland & Royal Australian College of General Practitioners.


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Journal ArticleDOI
TL;DR: A deprescribing protocol is proposed comprising 5 steps: ascertain all drugs the patient is currently taking and the reasons for each one, and prioritize drugs for discontinuation that have the lowest benefit-harm ratio and lowest likelihood of adverse withdrawal reactions or disease rebound syndromes.
Abstract: Inappropriate polypharmacy, especially in older people, imposes a substantial burden of adverse drug events, ill health, disability, hospitalization, and even death. The single most important predictor of inappropriate prescribing and risk of adverse drug events in older patients is the number of prescribed drugs. Deprescribing is the process of tapering or stopping drugs, aimed at minimizing polypharmacy and improving patient outcomes. Evidence of efficacy for deprescribing is emerging from randomized trials and observational studies. A deprescribing protocol is proposed comprising 5 steps: (1) ascertain all drugs the patient is currently taking and the reasons for each one; (2) consider overall risk of drug-induced harm in individual patients in determining the required intensity of deprescribing intervention; (3) assess each drug in regard to its current or future benefit potential compared with current or future harm or burden potential; (4) prioritize drugs for discontinuation that have the lowest benefit-harm ratio and lowest likelihood of adverse withdrawal reactions or disease rebound syndromes; and (5) implement a discontinuation regimen and monitor patients closely for improvement in outcomes or onset of adverse effects. Whereas patient and prescriber barriers to deprescribing exist, resources and strategies are available that facilitate deliberate yet judicious deprescribing and deserve wider application.

1,009 citations

Journal ArticleDOI
TL;DR: The highest quality cluster-RCTs suggest respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around younger children, as well asSimple and low-cost interventions would be useful for reducing transmission of epidemic respiratory viruses.
Abstract: Background Viral epidemics or pandemics of acute respiratory infections like influenza or severe acute respiratory syndrome pose a global threat. Antiviral drugs and vaccinations may be insufficient to prevent their spread. Objectives To review the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses. Search methods We searched The Cochrane Library, the Cochrane Central Register of Controlled Trials (CENTRAL 2010, Issue 3), which includes the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to October 2010), OLDMEDLINE (1950 to 1965), EMBASE (1990 to October 2010), CINAHL (1982 to October 2010), LILACS (2008 to October 2010), Indian MEDLARS (2008 to October 2010) and IMSEAR (2008 to October 2010). Selection criteria In this update, two review authors independently applied the inclusion criteria to all identified and retrieved articles and extracted data. We scanned 3775 titles, excluded 3560 and retrieved full papers of 215 studies, to include 66 papers of 67 studies. We included physical interventions (screening at entry ports, isolation, quarantine, social distancing, barriers, personal protection, hand hygiene) to prevent respiratory virus transmission. We included randomised controlled trials (RCTs), cohorts, case-controls, before-after and time series studies. Data collection and analysis We used a standardised form to assess trial eligibility. We assessed RCTs by randomisation method, allocation generation, concealment, blinding and follow up. We assessed non-RCTs for potential confounders and classified them as low, medium and high risk of bias. Main results We included 67 studies including randomised controlled trials and observational studies with a mixed risk of bias. A total number of participants is not included as the total would be made up of a heterogenous set of observations (participant people, observations on participants and countries (object of some studies)). The risk of bias for five RCTs and most cluster-RCTs was high. Observational studies were of mixed quality. Only case-control data were sufficiently homogeneous to allow meta-analysis. The highest quality cluster-RCTs suggest respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around younger children. Benefit from reduced transmission from children to household members is broadly supported also in other study designs where the potential for confounding is greater. Nine case-control studies suggested implementing transmission barriers, isolation and hygienic measures are effective at containing respiratory virus epidemics. Surgical masks or N95 respirators were the most consistent and comprehensive supportive measures. N95 respirators were non-inferior to simple surgical masks but more expensive, uncomfortable and irritating to skin. Adding virucidals or antiseptics to normal handwashing to decrease respiratory disease transmission remains uncertain. Global measures, such as screening at entry ports, led to a non-significant marginal delay in spread. There was limited evidence that social distancing was effective, especially if related to the risk of exposure. Authors' conclusions Simple and low-cost interventions would be useful for reducing transmission of epidemic respiratory viruses. Routine long-term implementation of some measures assessed might be difficult without the threat of an epidemic.

633 citations

Journal ArticleDOI
TL;DR: Antibiotics confer relative benefits in the treatment of sore throat, however, the absolute benefits are modest and protecting sore throat sufferers against suppurative and non-suppurative complications in modern Western society can be achieved only by treating with antibiotics.
Abstract: BACKGROUND: Sore throat is a very common reason for people to seek medical care. It is a disease that remits spontaneously, that is, 'cure' is not dependent on treatment. Nonetheless primary care doctors commonly prescribe antibiotics for sore throat and other upper respiratory tract infections. OBJECTIVES: To assess the benefits of antibiotics in the management of sore throat. SEARCH STRATEGY: Systematic search of the literature from 1945 to 2003, using electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, issue 2, 2003); MEDLINE (January 1966 to May 2003); EMBASE (January 1990 to March 2003), and the reference sections of the articles identified. We applied no language restrictions. We used abstracts of identified articles to identify trials. SELECTION CRITERIA: Trials of antibiotic against control with either measures of the typical symptoms (throat soreness, headache or fever), or suppurative complications (meaning: forming pus) and non-suppurative complications of sore throat. DATA COLLECTION AND ANALYSIS: Two reviewers independently screened potential studies for inclusion and resolved differences in opinion by discussion. The reviewers then independently extracted the data from the selected studies. We contacted the authors of three studies to acquire additional information not available in published articles.Potential studies were screened independently by two reviewers for inclusion, with differences in opinion resolved by discussion. Data was then independently extracted from studies selected by inclusion by two reviewers. Authors of three studies were contacted to acquire additional information not available in published articles. MAIN RESULTS: We included twenty-six studies, covering 12,669 cases of sore throat in the review.1. Non-suppurative complications There was a trend for protection against acute glomerulonephritis by antibiotics, but insufficient cases were recorded to be sure of this effect. Several studies found that antibiotics reduced acute rheumatic fever, to less than one third (odds ratio (OR) = 0.30; 95% confidence interval (CI) = 0.20 to 0.45). 2. Suppurative complications Antibiotics reduced the incidence of acute otitis media to about one quarter of that in the placebo group (OR = 0.22; 95% CI 0.11 to 0.43) and reduced the incidence of acute sinusitis to about one half of that in the placebo group (OR = 0.46; 95% CI 0.10 to 2.05). The incidence of quinsy was also reduced in relation to placebo group (OR = 0.16; 95% CI 0.07 to 0.35). 3. Symptoms Symptoms of headache, throat soreness and fever were reduced by antibiotics to about one half. The greatest time for this to be evident was at about three and a half days (when the symptoms of about 50% of untreated patients had settled). About 90% of treated and untreated patients were free of symptoms by one week. The overall number needed to treat to prevent one sore throat at day three was about 5.0 (95% CI 4.5 to 5.8); and at one week was 14.2 (95% CI 11.5 to 20.6). 4. Subgroup analyses of symptom reduction Subgroup analysis by age; blind versus unblinded; or use of antipyretics yielded no significant differences. The results of swabs of the throat for Streptococcus influenced the effect of antibiotics. If the swab was positive, antibiotics were more effective (the OR reduced to 0.16, 95% CI 0.09 to 0.26) than if it was negative (OR 0.65; 95% CI 0.38 to 1.12). REVIEWERS' CONCLUSIONS: Antibiotics confer relative benefits in the treatment of sore throat. However, the absolute benefits are modest. Protecting sore throat sufferers against suppurative and non-suppurative complications in modern Western society can be achieved only by treating with antibiotics many who will derive no benefit. In emerging economies where rates of for example acute rheumatic fever are high, the number needed to treat may be much lower. Antibiotics shorten the duration of symptoms by a mean of one day about half way through the illness (the time of maximal effect), and by about sixteen hours overall.

566 citations

Journal ArticleDOI
10 Jan 2008-BMJ
TL;DR: Routine long term implementation of some of the measures to interrupt or reduce the spread of respiratory viruses might be difficult, however, many simple and low cost interventions reduce the transmission of epidemic respiratory viruses.
Abstract: Objective To systematically review evidence for the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses. Data extraction Search strategy of the Cochrane Library, Medline, OldMedline, Embase, and CINAHL, without language restriction, for any intervention to prevent transmissionofrespiratoryviruses(isolation,quarantine, social distancing, barriers, personal protection, and hygiene). Study designs were randomised trials, cohort studies, case-control studies, and controlled before and after studies. Data synthesis Of 2300 titles scanned 138 full papers were retrieved, including 49 papers of 51 studies. Study qualitywaspoorforthethreerandomisedcontrolledtrials and most of the cluster randomised controlled trials; the observational studies were of mixed quality. Heterogeneity precluded meta-analysis of most data except that from six case-control studies. The highest quality cluster randomised trials suggest that the spread of respiratory viruses into the community can be prevented by intervening with hygienic measures aimed at younger children. Meta-analysis of six case-control studies suggests that physical measures are highly effective in preventing the spread of SARS: handwashing more than 10 times daily (odds ratio 0.45, 95% confidence interval 0.36 to 0.57; number needed to treat =4, 95% confidence interval 3.65 to 5.52); wearing masks (0.32, 0.25 to 0.40; NNT=6, 4.54 to 8.03); wearing N95 masks (0.09, 0.03 to 0.30; NNT=3, 2.37 to 4.06); wearing gloves (0.43, 0.29 to 0.65; NNT=5, 4.15 to 15.41); wearing gowns (0.23, 0.14 to 0.37; NNT=5, 3.37 to 7.12); and handwashing, masks, gloves, and gowns combined (0.09, 0.02 to 0.35; NNT=3, 2.66 to 4.97). The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease the spread of respiratory disease remains uncertain. The lack of proper evaluation of global measures such as screening at entry ports and social distancing prevent firm conclusions being drawn. Conclusion Routine long term implementation of some physical measures to interrupt or reduce the spread of

555 citations

Journal ArticleDOI
TL;DR: The majority of participants overestimated intervention benefit and underestimated harm and Clinicians should discuss accurate and balanced information about intervention benefits and harms with patients, providing the opportunity to develop realistic expectations and make informed decisions.
Abstract: Importance Unrealistic patient expectations of the benefits and harms of interventions can influence decision making and may be contributing to increasing intervention uptake and health care costs. Objective To systematically review all studies that have quantitatively assessed patients’ expectations of the benefits and/or harms of any treatment, test, or screening test. Evidence Review A comprehensive search strategy was used in 4 databases (MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, PsycINFO) up to June 2013, with no language or study type restriction. We also ran cited reference searches of included studies and contacted experts and study authors. Two researchers independently evaluated methodological quality and extracted participants’ estimates of benefit and harms and authors’ contemporaneous estimates. Findings Of the 15 343 records screened, 36 articles (from 35 studies) involving a total of 27 323 patients were eligible. Fourteen studies focused on a screen, 15 on treatment, 3 a test, and 3 on treatment and screening. More studies assessed only benefit expectations (22 [63%]) than benefit and harm expectations (10 [29%]) or only harm (3 [8%]). Fifty-four outcomes (across 32 studies) assessed benefit expectations: of the 34 outcomes with overestimation data available, the majority of participants overestimated benefit for 22 (65%) of them. For 17 benefit expectation outcomes, we could not calculate the proportion of participants who overestimated or underestimated, although for 15 (88%) of these, study authors concluded that participants overestimated benefits. Expectations of harm were assessed by 27 outcomes (across 13 studies): underestimation data were available for 15 outcomes and the majority of participants underestimated harm for 10 (67%) of these. A correct estimation by at least 50% of participants only occurred for 2 outcomes about benefit expectations and 2 outcomes about harm expectations. Conclusions and Relevance The majority of participants overestimated intervention benefit and underestimated harm. Clinicians should discuss accurate and balanced information about intervention benefits and harms with patients, providing the opportunity to develop realistic expectations and make informed decisions.

550 citations


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TL;DR: This report updates the 2000 recommendations by the Advisory Committee on Immunization Practices on the use of influenza vaccine and antiviral agents with new or updated information regarding the cost-effectiveness of influenza vaccination and the 2001-2002 trivalent vaccine virus strains.
Abstract: This report updates the 2002 recommendations by the Advisory Committee on Immunization Practices (ACIP) on the use of influenza vaccine and antiviral agents (CDC. Prevention and Control of Influenza: Recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2002;51 [No. RR-3]:1-31). The 2003 recommendations include new or updated information regarding 1) the timing of influenza vaccination by age and risk group; 2) influenza vaccine for children aged 6-23 months; 3) the 2003-2004 trivalent inactivated vaccine virus strains: A/Moscow/10/99 (H3N2)-like, A/New Caledonia/20/99 (H1N1)-like, and B/Hong Kong/330/2001-like antigens (for the A/Moscow/10/99 [H3N2]-like antigen, manufacturers will use the antigenically equivalent A/Panama/2007/99 [H3N2] virus, and for the B/Hong Kong/330/2001-like antigen, manufacturers will use either B/Hong Kong/330/2001 or the antigenically equivalent B/Hong Kong/1434/2002); 4) availability of certain influenza vaccine doses with reduced thimerosal content, including single 0.25 mL-dose syringes; and 5) manufacturers of influenza vaccine for the U.S. market. Although the optimal time to vaccinate against influenza is October and November, vaccination in December and later continues to be strongly recommended A link to this report and other information regarding influenza can be accessed at http://www.cdc.gov/ncidod/diseases/flu/fluvirus.htm.

5,334 citations

01 Feb 2009
TL;DR: This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale, and what might be coming next.
Abstract: Secret History: Return of the Black Death Channel 4, 7-8pm In 1348 the Black Death swept through London, killing people within days of the appearance of their first symptoms. Exactly how many died, and why, has long been a mystery. This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale. And they ask, what might be coming next?

5,234 citations

Journal ArticleDOI
TL;DR: Decision aids reduced the proportion of undecided participants and appeared to have a positive effect on patient-clinician communication, and those exposed to a decision aid were either equally or more satisfied with their decision, the decision-making process, and the preparation for decision making compared to usual care.
Abstract: Background Decision aids are intended to help people participate in decisions that involve weighing the benefits and harms of treatment options often with scientific uncertainty. Objectives To assess the effects of decision aids for people facing treatment or screening decisions. Search methods For this update, we searched from 2009 to June 2012 in MEDLINE; CENTRAL; EMBASE; PsycINFO; and grey literature. Cumulatively, we have searched each database since its start date including CINAHL (to September 2008). Selection criteria We included published randomized controlled trials of decision aids, which are interventions designed to support patients' decision making by making explicit the decision, providing information about treatment or screening options and their associated outcomes, compared to usual care and/or alternative interventions. We excluded studies of participants making hypothetical decisions. Data collection and analysis Two review authors independently screened citations for inclusion, extracted data, and assessed risk of bias. The primary outcomes, based on the International Patient Decision Aid Standards (IPDAS), were: A) 'choice made' attributes; B) 'decision-making process' attributes. Secondary outcomes were behavioral, health, and health-system effects. We pooled results using mean differences (MD) and relative risks (RR), applying a random-effects model. Main results This update includes 33 new studies for a total of 115 studies involving 34,444 participants. For risk of bias, selective outcome reporting and blinding of participants and personnel were mostly rated as unclear due to inadequate reporting. Based on 7 items, 8 of 115 studies had high risk of bias for 1 or 2 items each. Of 115 included studies, 88 (76.5%) used at least one of the IPDAS effectiveness criteria: A) 'choice made' attributes criteria: knowledge scores (76 studies); accurate risk perceptions (25 studies); and informed value-based choice (20 studies); and B) 'decision-making process' attributes criteria: feeling informed (34 studies) and feeling clear about values (29 studies). A) Criteria involving 'choice made' attributes: Compared to usual care, decision aids increased knowledge (MD 13.34 out of 100; 95% confidence interval (CI) 11.17 to 15.51; n = 42). When more detailed decision aids were compared to simple decision aids, the relative improvement in knowledge was significant (MD 5.52 out of 100; 95% CI 3.90 to 7.15; n = 19). Exposure to a decision aid with expressed probabilities resulted in a higher proportion of people with accurate risk perceptions (RR 1.82; 95% CI 1.52 to 2.16; n = 19). Exposure to a decision aid with explicit values clarification resulted in a higher proportion of patients choosing an option congruent with their values (RR 1.51; 95% CI 1.17 to 1.96; n = 13). B) Criteria involving 'decision-making process' attributes: Decision aids compared to usual care interventions resulted in: a) lower decisional conflict related to feeling uninformed (MD -7.26 of 100; 95% CI -9.73 to -4.78; n = 22) and feeling unclear about personal values (MD -6.09; 95% CI -8.50 to -3.67; n = 18); b) reduced proportions of people who were passive in decision making (RR 0.66; 95% CI 0.53 to 0.81; n = 14); and c) reduced proportions of people who remained undecided post-intervention (RR 0.59; 95% CI 0.47 to 0.72; n = 18). Decision aids appeared to have a positive effect on patient-practitioner communication in all nine studies that measured this outcome. For satisfaction with the decision (n = 20), decision-making process (n = 17), and/or preparation for decision making (n = 3), those exposed to a decision aid were either more satisfied, or there was no difference between the decision aid versus comparison interventions. No studies evaluated decision-making process attributes for helping patients to recognize that a decision needs to be made, or understanding that values affect the choice. C) Secondary outcomes Exposure to decision aids compared to usual care reduced the number of people of choosing major elective invasive surgery in favour of more conservative options (RR 0.79; 95% CI 0.68 to 0.93; n = 15). Exposure to decision aids compared to usual care reduced the number of people choosing to have prostate-specific antigen screening (RR 0.87; 95% CI 0.77 to 0.98; n = 9). When detailed compared to simple decision aids were used, fewer people chose menopausal hormone therapy (RR 0.73; 95% CI 0.55 to 0.98; n = 3). For other decisions, the effect on choices was variable. The effect of decision aids on length of consultation varied from 8 minutes shorter to 23 minutes longer (median 2.55 minutes longer) with 2 studies indicating statistically-significantly longer, 1 study shorter, and 6 studies reporting no difference in consultation length. Groups of patients receiving decision aids do not appear to differ from comparison groups in terms of anxiety (n = 30), general health outcomes (n = 11), and condition-specific health outcomes (n = 11). The effects of decision aids on other outcomes (adherence to the decision, costs/resource use) were inconclusive. Authors' conclusions There is high-quality evidence that decision aids compared to usual care improve people's knowledge regarding options, and reduce their decisional conflict related to feeling uninformed and unclear about their personal values. There is moderate-quality evidence that decision aids compared to usual care stimulate people to take a more active role in decision making, and improve accurate risk perceptions when probabilities are included in decision aids, compared to not being included. There is low-quality evidence that decision aids improve congruence between the chosen option and the patient's values. New for this updated review is further evidence indicating more informed, values-based choices, and improved patient-practitioner communication. There is a variable effect of decision aids on length of consultation. Consistent with findings from the previous review, decision aids have a variable effect on choices. They reduce the number of people choosing discretionary surgery and have no apparent adverse effects on health outcomes or satisfaction. The effects on adherence with the chosen option, cost-effectiveness, use with lower literacy populations, and level of detail needed in decision aids need further evaluation. Little is known about the degree of detail that decision aids need in order to have a positive effect on attributes of the choice made, or the decision-making process.

5,042 citations

01 Jan 2009
TL;DR: Physicians should consider modification of immunosuppressive regimens to decrease the risk of PTD in high-risk transplant recipients and Randomized trials are needed to evaluate the use of oral glucose-lowering agents in transplant recipients.
Abstract: OBJECTIVE — To systematically review the incidence of posttransplantation diabetes (PTD), risk factors for its development, prognostic implications, and optimal management. RESEARCH DESIGN AND METHODS — We searched databases (MEDLINE, EMBASE, the Cochrane Library, and others) from inception to September 2000, reviewed bibliographies in reports retrieved, contacted transplantation experts, and reviewed specialty journals. Two reviewers independently determined report inclusion (original studies, in all languages, of PTD in adults with no history of diabetes before transplantation), assessed study methods, and extracted data using a standardized form. Meta-regression was used to explain between-study differences in incidence. RESULTS — Nineteen studies with 3,611 patients were included. The 12-month cumulative incidence of PTD is lower (10% in most studies) than it was 3 decades ago. The type of immunosuppression explained 74% of the variability in incidence (P 0.0004). Risk factors were patient age, nonwhite ethnicity, glucocorticoid treatment for rejection, and immunosuppression with high-dose cyclosporine and tacrolimus. PTD was associated with decreased graft and patient survival in earlier studies; later studies showed improved outcomes. Randomized trials of treatment regimens have not been conducted. CONCLUSIONS — Physicians should consider modification of immunosuppressive regimens to decrease the risk of PTD in high-risk transplant recipients. Randomized trials are needed to evaluate the use of oral glucose-lowering agents in transplant recipients, paying particular attention to interactions with immunosuppressive drugs. Diabetes Care 25:583–592, 2002

3,716 citations

Book ChapterDOI
30 May 2018
TL;DR: Tata Africa Services (Nigeria) Limited as mentioned in this paper is a nodal point for Tata businesses in West Africa and operates as the hub of TATA operations in Nigeria and the rest of West Africa.
Abstract: Established in 2006, TATA Africa Services (Nigeria) Limited operates as the nodal point for Tata businesses in West Africa. TATA Africa Services (Nigeria) Limited has a strong presence in Nigeria with investments exceeding USD 10 million. The company was established in Lagos, Nigeria as a subsidiary of TATA Africa Holdings (SA) (Pty) Limited, South Africa and serves as the hub of Tata’s operations in Nigeria and the rest of West Africa.

3,658 citations