- Email: [email protected]
Calcium-based phosphate binders and chronic kidney disease
Correspondence
Published Online November 14, 2013 http://dx.doi.org/10.1016/ S0140-6736(13)62223-0
The target of reversal of the spread of tuberculosis by 2015 is far from being achieved at country level. Reported tuberculosis figures in Mozambique are still following an upward trend, which are hardly explained by an improved case detection rate which, according to WHO estimates, remains worryingly stable at only 34%, the lowest among the high-burden countries. Thus, the true magnitude of the disease burden is unknown and current estimates are far from precise. Childhood tuberculosis continues to be relatively neglected and, in Mozambique, a country in which almost 50% of the population is younger than 15 years, the lack of childhood tuberculosis estimates only perpetuates and magnifies the problem. Moreover, the current surveillance system only detects 16% of the estimated total number of multidrug-resistant tuberculosis cases3 posing a dramatic challenge for the near future. As a country with one of the highest tuberculosis/ HIV co-infection rates, ensuring prompt diagnosis and treatment of tuberculosis through newly available technology (ie, Gene Xpert) and ensuring high antiretroviral therapy coverage, is not a minor undertaking and is regarded as a top health priority by the government. For countries such as Mozambique, the Global TB report identifies the need for targeted efforts to improve the tuberculosis surveillance system, which should be integrated with HIV surveillance efforts. Within this framework, operational research needs cannot be overlooked since they will provide improved estimates of disease burden and identify programme failures and priority areas for action and improvement. Political commitment to sustain and increase national and international donors’ budget allocations to tuberculosis control and research is crucial in order to relieve this longstanding scourge. We declare that we have no conflicts of interest.
216
*Alberto L García-Basteiro, Elisa López-Varela, Ivan Manhiça, Eusebio Macete, Pedro L Alonso [email protected] Manhiça Health Research Center, Vila da Manhiça, Maputo, Mozambique (ALG-B, EL-V, EM, PLA); Barcelona Centre for International Health Research CRESIB, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain (ALG-B, EL-V, PLA); and National Tuberculosis Program, Ministry of Health, Maputo, Mozambique (IM) 1
2
3
WHO. Global tuberculosis report 2013. Geneva: World Health Organization, 2013. http://www. who.int/tb/publications/global_report/en/ index.html (accessed Oct 23, 2013). Zumla A, George A, Sharma V, Herbert N, Baroness Masham of Ilton. WHO’s 2013 global report on tuberculosis: successes, threats, and opportunities. Lancet 2013; 382: 1765–67. Falzon D, Jaramillo E, Wares F, Zignol M, Floyd K, Raviglione MC. Universal access to care for multidrug-resistant tuberculosis: an analysis of surveillance data. Lancet Infect Dis 2013; 13: 690–97.
protocol (and not intention-to-treat analysis) and patients were censored at dialysis inception (thus mortality after dialysis initiation was not reported) despite all cause mortality being the primary outcome. Neither the patients nor the investigators were blinded, and the categorisation of this trial5 as low risk of bias is questionable. Exclusion of this trial on sensitivity analysis leads to a revised RR of 0·82 (95% CI 0·66–1·04). On the basis of these issues, the conclusion of the superiority of calciumbased phosphate binders in reducing mortality is not robust. We declare that we have no conflicts of interest.
*Swapnil Hiremath, Ayub Akbari [email protected] University of Ottawa, Ottawa, ON K1H 7W9, Canada 1
Calcium-based phosphate binders and chronic kidney disease We have concerns regarding Sophie Jamal and colleagues’ Article (Oct 12, p 1268)1 on the effect of calcium-based versus non-calciumbased phosphate binders on mortality in patients with chronic kidney disease. First, Suki and colleagues’ large randomised controlled trial with 2103 patients and 542 events was a well done negative trial and should be considered while interpreting the present results.2 The forest plot (figure 2)1 strongly suggests a small-study effect;3 indeed a subgroup analysis of small (<50 events; RR 0·54, 95% CI 0·37–0·79) versus large (>50 events; RR 0·93, 95% CI 0·82–1·04) trials shows a significant difference in effect size. This also resolves the heterogeneity with I2 values of 0. Second, we found that the Duval‘s trim and fill analysis4 for publication bias using the correct options does add three studies with an adjusted value of the RR being 0·82 (95% CI 0·64–1·04). Lastly, the trial by Di Iorio and colleagues had a correction,5 it was not registered, it was reported per
2
3
4
5
Jamal SA, Vandermeer B, Raggi P, et al. Effect of calcium-based versus non-calcium-based phosphate binders on mortality in patients with chronic kidney disease: an updated systematic review and meta-analysis. Lancet 2013; 382: 1268–77. Suki WN. Effects of sevelamer and calciumbased phosphate binders on mortality in hemodialysis patients: results of a randomized clinical trial. J Ren Nutr 2008; 18: 91–98. Nuesch E, Trelle S, Reichenbach S, et al. Small study effects in meta-analyses of osteoarthritis trials: meta-epidemiological study. BMJ 2010; 341: c3515. Duval S, Tweedie R. Trim and fill: a simple funnel-plot-based method of testing and adjusting for publication bias in meta-analysis. Biometrics 2000; 56: 455-63. Di Iorio D. Correction. http://cjasn.asnjournals. org/content/7/8/1370 (accessed July 31, 2013).
Polio and the risk for the European Union Martin Eichner and Stefan Brockmann warn that “Vaccinating only Syrian refugees—as has been recommended by the ECDC—must be judged as insufficient; more comprehensive measures should be taken into consideration.”1 In response to the recent developments regarding wild-type polio virus (WPV) circulation in Israel and a cluster of poliomyelitis cases in Syria, the European Centre for Disease Prevention and Control (ECDC) has published two risk assessments for www.thelancet.com Vol 383 January 18, 2014
Published Online November 14, 2013 http://dx.doi.org/10.1016/ S0140-6736(13)62223-0
The target of reversal of the spread of tuberculosis by 2015 is far from being achieved at country level. Reported tuberculosis figures in Mozambique are still following an upward trend, which are hardly explained by an improved case detection rate which, according to WHO estimates, remains worryingly stable at only 34%, the lowest among the high-burden countries. Thus, the true magnitude of the disease burden is unknown and current estimates are far from precise. Childhood tuberculosis continues to be relatively neglected and, in Mozambique, a country in which almost 50% of the population is younger than 15 years, the lack of childhood tuberculosis estimates only perpetuates and magnifies the problem. Moreover, the current surveillance system only detects 16% of the estimated total number of multidrug-resistant tuberculosis cases3 posing a dramatic challenge for the near future. As a country with one of the highest tuberculosis/ HIV co-infection rates, ensuring prompt diagnosis and treatment of tuberculosis through newly available technology (ie, Gene Xpert) and ensuring high antiretroviral therapy coverage, is not a minor undertaking and is regarded as a top health priority by the government. For countries such as Mozambique, the Global TB report identifies the need for targeted efforts to improve the tuberculosis surveillance system, which should be integrated with HIV surveillance efforts. Within this framework, operational research needs cannot be overlooked since they will provide improved estimates of disease burden and identify programme failures and priority areas for action and improvement. Political commitment to sustain and increase national and international donors’ budget allocations to tuberculosis control and research is crucial in order to relieve this longstanding scourge. We declare that we have no conflicts of interest.
216
*Alberto L García-Basteiro, Elisa López-Varela, Ivan Manhiça, Eusebio Macete, Pedro L Alonso [email protected] Manhiça Health Research Center, Vila da Manhiça, Maputo, Mozambique (ALG-B, EL-V, EM, PLA); Barcelona Centre for International Health Research CRESIB, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain (ALG-B, EL-V, PLA); and National Tuberculosis Program, Ministry of Health, Maputo, Mozambique (IM) 1
2
3
WHO. Global tuberculosis report 2013. Geneva: World Health Organization, 2013. http://www. who.int/tb/publications/global_report/en/ index.html (accessed Oct 23, 2013). Zumla A, George A, Sharma V, Herbert N, Baroness Masham of Ilton. WHO’s 2013 global report on tuberculosis: successes, threats, and opportunities. Lancet 2013; 382: 1765–67. Falzon D, Jaramillo E, Wares F, Zignol M, Floyd K, Raviglione MC. Universal access to care for multidrug-resistant tuberculosis: an analysis of surveillance data. Lancet Infect Dis 2013; 13: 690–97.
protocol (and not intention-to-treat analysis) and patients were censored at dialysis inception (thus mortality after dialysis initiation was not reported) despite all cause mortality being the primary outcome. Neither the patients nor the investigators were blinded, and the categorisation of this trial5 as low risk of bias is questionable. Exclusion of this trial on sensitivity analysis leads to a revised RR of 0·82 (95% CI 0·66–1·04). On the basis of these issues, the conclusion of the superiority of calciumbased phosphate binders in reducing mortality is not robust. We declare that we have no conflicts of interest.
*Swapnil Hiremath, Ayub Akbari [email protected] University of Ottawa, Ottawa, ON K1H 7W9, Canada 1
Calcium-based phosphate binders and chronic kidney disease We have concerns regarding Sophie Jamal and colleagues’ Article (Oct 12, p 1268)1 on the effect of calcium-based versus non-calciumbased phosphate binders on mortality in patients with chronic kidney disease. First, Suki and colleagues’ large randomised controlled trial with 2103 patients and 542 events was a well done negative trial and should be considered while interpreting the present results.2 The forest plot (figure 2)1 strongly suggests a small-study effect;3 indeed a subgroup analysis of small (<50 events; RR 0·54, 95% CI 0·37–0·79) versus large (>50 events; RR 0·93, 95% CI 0·82–1·04) trials shows a significant difference in effect size. This also resolves the heterogeneity with I2 values of 0. Second, we found that the Duval‘s trim and fill analysis4 for publication bias using the correct options does add three studies with an adjusted value of the RR being 0·82 (95% CI 0·64–1·04). Lastly, the trial by Di Iorio and colleagues had a correction,5 it was not registered, it was reported per
2
3
4
5
Jamal SA, Vandermeer B, Raggi P, et al. Effect of calcium-based versus non-calcium-based phosphate binders on mortality in patients with chronic kidney disease: an updated systematic review and meta-analysis. Lancet 2013; 382: 1268–77. Suki WN. Effects of sevelamer and calciumbased phosphate binders on mortality in hemodialysis patients: results of a randomized clinical trial. J Ren Nutr 2008; 18: 91–98. Nuesch E, Trelle S, Reichenbach S, et al. Small study effects in meta-analyses of osteoarthritis trials: meta-epidemiological study. BMJ 2010; 341: c3515. Duval S, Tweedie R. Trim and fill: a simple funnel-plot-based method of testing and adjusting for publication bias in meta-analysis. Biometrics 2000; 56: 455-63. Di Iorio D. Correction. http://cjasn.asnjournals. org/content/7/8/1370 (accessed July 31, 2013).
Polio and the risk for the European Union Martin Eichner and Stefan Brockmann warn that “Vaccinating only Syrian refugees—as has been recommended by the ECDC—must be judged as insufficient; more comprehensive measures should be taken into consideration.”1 In response to the recent developments regarding wild-type polio virus (WPV) circulation in Israel and a cluster of poliomyelitis cases in Syria, the European Centre for Disease Prevention and Control (ECDC) has published two risk assessments for www.thelancet.com Vol 383 January 18, 2014