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1. Empagliflozin, Health Status, and Quality of Life in Patients With Heart Failure and Preserved Ejection Fraction: The EMPEROR-Preserved Trial

Author

Butler, J, Filippatos, G, Jamal Siddiqi, T, Brueckmann, M, Bohm, M, Chopra, V, Pedro Ferreira, J, Januzzi, J, Kaul, S, Pina, I, Ponikowski, P, Shah, S, Senni, M, Vedin, O, Verma, S, Peil, B, Pocock, S, Zannad, F, Packer, M, Anker, S, Butler J., Filippatos G., Jamal Siddiqi T., Brueckmann M., Bohm M., Chopra V. K., Pedro Ferreira J., Januzzi J. L., Kaul S., Pina I. L., Ponikowski P., Shah S. J., Senni M., Vedin O., Verma S., Peil B., Pocock S. J., Zannad F., Packer M., Anker S. D., Butler, J, Filippatos, G, Jamal Siddiqi, T, Brueckmann, M, Bohm, M, Chopra, V, Pedro Ferreira, J, Januzzi, J, Kaul, S, Pina, I, Ponikowski, P, Shah, S, Senni, M, Vedin, O, Verma, S, Peil, B, Pocock, S, Zannad, F, Packer, M, Anker, S, Butler J., Filippatos G., Jamal Siddiqi T., Brueckmann M., Bohm M., Chopra V. K., Pedro Ferreira J., Januzzi J. L., Kaul S., Pina I. L., Ponikowski P., Shah S. J., Senni M., Vedin O., Verma S., Peil B., Pocock S. J., Zannad F., Packer M., and Anker S. D.

Abstract

Background: Patients with heart failure with preserved ejection fraction have significant impairment in health-related quality of life. In the EMPEROR-Preserved trial (Empagliflozin Outcome Trial in Patients With Chronic Heart Failure With Preserved Ejection Fraction), we evaluated the efficacy of empagliflozin on health-related quality of life in patients with heart failure with preserved ejection fraction and whether the clinical benefit observed with empagliflozin varies according to baseline health status. Methods: Health-related quality of life was measured with the Kansas City Cardiomyopathy Questionnaire (KCCQ) at baseline and 12, 32, and 52 weeks. Patients were divided by baseline KCCQ Clinical Summary Score (CSS) tertiles, and the effect of empagliflozin on outcomes was examined. The effect of empagliflozin on KCCQ-CSS, Total Symptom Score, and Overall Summary Score was evaluated. Responder analyses were performed to compare the odds of improvement and deterioration in KCCQ related to treatment with empagliflozin. Results: The effect of empagliflozin on reducing the risk of time to cardiovascular death or heart failure hospitalization was consistent across baseline KCCQ-CSS tertiles (hazard ratio, 0.83 [95% CI, 0.69-1.00], 0.70 [95% CI, 0.55-0.88], and 0.82 [95% CI, 0.62-1.08] for scores <62.5, 62.5-83.3, and ≥83.3, respectively; P trend=0.77). Similar results were seen for total heart failure hospitalizations. Patients treated with empagliflozin had significant improvement in KCCQ-CSS versus placebo (+1.03, +1.24, and +1.50 at 12, 32, and 52 weeks, respectively; P<0.01); similar results were seen for Total Symptom Score and Overall Summary Score. At 12 weeks, patients on empagliflozin had higher odds of improvement ≥5 points (odds ratio, 1.23 [95% CI, 1.10-1.37]), ≥10 points (odds ratio, 1.15 [95% CI, 1.03-1.27]), and ≥15 points (odds ratio, 1.13 [95% CI, 1.02-1.26]) and lower odds of deterioration ≥5 points in KCCQ-CSS (odds ratio, 0.85 [95% CI, 0.7

Published
2022

2. Evaluation of the effect of sodium–glucose co-transporter 2 inhibition with empagliflozin on morbidity and mortality of patients with chronic heart failure and a reduced ejection fraction: rationale for and design of the EMPEROR-Reduced trial

Author

Packer, M, Butler, J, Filippatos, G, Jamal, W, Salsali, A, Schnee, J, Kimura, K, Zeller, C, George, J, Brueckmann, M, Anker, S, Zannad, F, Perrone, S, Nicholls, S, Janssens, S, Bocchi, E, Giannetti, N, Verma, S, Jian, Z, Spinar, J, Seronde, M, Bohm, M, Merkely, B, Chopra, V, Senni, M, Taddei, S, Tsutsui, H, Choi, D, Chuquiure, E, La Rocca, H, Ponikowski, P, Juanatey, J, Squire, I, Januzzi, J, Pina, I, Pocock, S, Carson, P, Doehner, W, Miller, A, Haas, M, Pehrson, S, Komajda, M, Anand, I, Teerlink, J, Rabinstein, A, Steiner, T, Kamel, H, Tsivgoulis, G, Lewis, J, Freston, J, Kaplowitz, N, Mann, J, Petrie, M, Bernstein, R, Cheung, A, Green, J, Kaul, S, Ping, C, Lip, G, Marx, N, Mccullough, P, Mehta, C, Rosenstock, J, Sattar, N, Scirica, B, Wanner, C, Welty, F, Parhofer, K, Clayton, T, Pedersen, T, Lees, K, Konstam, M, Greenberg, B, Palmer, M, Packer M., Butler J., Filippatos G. S., Jamal W., Salsali A., Schnee J., Kimura K., Zeller C., George J., Brueckmann M., Anker S. D., Zannad F., Perrone S., Nicholls S., Janssens S., Bocchi E., Giannetti N., Verma S., Jian Z., Spinar J., Seronde M. -F., Bohm M., Merkely B., Chopra V., Senni M., Taddei S., Tsutsui H., Choi D. -J., Chuquiure E., La Rocca H. P. B., Ponikowski P., Juanatey J. R. G., Squire I., Januzzi J., Pina I., Pocock S. J., Carson P., Doehner W., Miller A., Haas M., Pehrson S., Komajda M., Anand I., Teerlink J., Rabinstein A., Steiner T., Kamel H., Tsivgoulis G., Lewis J., Freston J., Kaplowitz N., Mann J., Petrie M., Bernstein R., Cheung A., Green J., Kaul S., Ping C. L. S., Lip G., Marx N., McCullough P., Mehta C., Rosenstock J., Sattar N., Scirica B., Wanner C., Welty F. K., Parhofer K. G., Clayton T., Pedersen T. R., Lees K. R., Konstam M. A., Greenberg B., Palmer M., Packer, M, Butler, J, Filippatos, G, Jamal, W, Salsali, A, Schnee, J, Kimura, K, Zeller, C, George, J, Brueckmann, M, Anker, S, Zannad, F, Perrone, S, Nicholls, S, Janssens, S, Bocchi, E, Giannetti, N, Verma, S, Jian, Z, Spinar, J, Seronde, M, Bohm, M, Merkely, B, Chopra, V, Senni, M, Taddei, S, Tsutsui, H, Choi, D, Chuquiure, E, La Rocca, H, Ponikowski, P, Juanatey, J, Squire, I, Januzzi, J, Pina, I, Pocock, S, Carson, P, Doehner, W, Miller, A, Haas, M, Pehrson, S, Komajda, M, Anand, I, Teerlink, J, Rabinstein, A, Steiner, T, Kamel, H, Tsivgoulis, G, Lewis, J, Freston, J, Kaplowitz, N, Mann, J, Petrie, M, Bernstein, R, Cheung, A, Green, J, Kaul, S, Ping, C, Lip, G, Marx, N, Mccullough, P, Mehta, C, Rosenstock, J, Sattar, N, Scirica, B, Wanner, C, Welty, F, Parhofer, K, Clayton, T, Pedersen, T, Lees, K, Konstam, M, Greenberg, B, Palmer, M, Packer M., Butler J., Filippatos G. S., Jamal W., Salsali A., Schnee J., Kimura K., Zeller C., George J., Brueckmann M., Anker S. D., Zannad F., Perrone S., Nicholls S., Janssens S., Bocchi E., Giannetti N., Verma S., Jian Z., Spinar J., Seronde M. -F., Bohm M., Merkely B., Chopra V., Senni M., Taddei S., Tsutsui H., Choi D. -J., Chuquiure E., La Rocca H. P. B., Ponikowski P., Juanatey J. R. G., Squire I., Januzzi J., Pina I., Pocock S. J., Carson P., Doehner W., Miller A., Haas M., Pehrson S., Komajda M., Anand I., Teerlink J., Rabinstein A., Steiner T., Kamel H., Tsivgoulis G., Lewis J., Freston J., Kaplowitz N., Mann J., Petrie M., Bernstein R., Cheung A., Green J., Kaul S., Ping C. L. S., Lip G., Marx N., McCullough P., Mehta C., Rosenstock J., Sattar N., Scirica B., Wanner C., Welty F. K., Parhofer K. G., Clayton T., Pedersen T. R., Lees K. R., Konstam M. A., Greenberg B., and Palmer M.

Abstract

Drugs that inhibit the sodium–glucose co-transporter 2 (SGLT2) have been shown to reduce the risk of hospitalizations for heart failure in patients with type 2 diabetes. In populations that largely did not have heart failure at the time of enrolment, empagliflozin, canagliflozin and dapagliflozin decreased the risk of serious new-onset heart failure events by ≈30%. In addition, in the EMPA-REG OUTCOME trial, empagliflozin reduced the risk of both pump failure and sudden deaths, the two most common modes of death among patients with heart failure. In none of the three trials could the benefits of SGLT2 inhibitors on heart failure be explained by the actions of these drugs as diuretics or anti-hyperglycaemic agents. These observations raise the possibility that SGLT2 inhibitors could reduce morbidity and mortality in patients with established heart failure, including those without diabetes. The EMPEROR-Reduced trial is enrolling ≈3600 patients with heart failure and a reduced left ventricular ejection fraction (≤ 40%), half of whom are expected not to have diabetes. Patients are being randomized to placebo or empagliflozin 10 mg daily, which is added to all appropriate treatment with inhibitors of the renin–angiotensin system and neprilysin, beta-blockers and mineralocorticoid receptor antagonists. The primary endpoint is the time-to-first event analysis of the combined risk of cardiovascular death and hospitalization for heart failure, but the trial will also evaluate the effects of empagliflozin on renal function, cardiovascular death, all-cause mortality, and recurrent hospitalization events. By adjusting eligibility based on natriuretic peptide levels to the baseline ejection fraction, the trial will preferentially enrol high-risk patients. A large proportion of the participants is expected to have an ejection fraction < 30%, and the estimated annual event rate is expected to be at least 15%. The EMPEROR-Reduced trial is well-positioned to determine if the addi

Published
2019

3. Evaluation of the effects of sodium–glucose co-transporter 2 inhibition with empagliflozin on morbidity and mortality in patients with chronic heart failure and a preserved ejection fraction: rationale for and design of the EMPEROR-Preserved Trial

Author

Anker, S, Butler, J, Filippatos, G, Jamal, W, Salsali, A, Schnee, J, Kimura, K, Zeller, C, George, J, Brueckmann, M, Zannad, F, Packer, M, Perrone, S, Nicholls, S, Janssens, S, Bocchi, E, Giannetti, N, Verma, S, Jian, Z, Gomez Mesa, J, Spinar, J, Bohm, M, Merkely, B, Chopra, V, Senni, M, Taddi, S, Tsutsui, H, Chuquiure, E, La Rocca, H, Ponikowski, P, Vinereanu, D, Sim, D, Choi, D, Juanatey, J, Squire, I, Januzzi, J, Pina, I, Pocock, S, Carson, P, Doehner, W, Miller, A, Haas, M, Pehrson, S, Komajda, M, Anand, I, Teerlink, J, Rabinstein, A, Steiner, T, Kamel, H, Tsivgoulis, G, Lewis, J, Freston, J, Kaplowitz, N, Mann, J, Petrie, M, Bernstein, R, Cheung, A, Green, J, Kaul, S, Ping, C, Lip, G, Marx, N, Mccullough, P, Mehta, C, Rosenstock, J, Sattar, N, Scirica, B, Wanner, C, Welty, F, Parhofer, K, Clayton, T, Pedersen, T, Lees, K, Konstam, M, Greenberg, B, Palmer, M, Anker S. D., Butler J., Filippatos G. S., Jamal W., Salsali A., Schnee J., Kimura K., Zeller C., George J., Brueckmann M., Zannad F., Packer M., Perrone S., Nicholls S., Janssens S., Bocchi E., Giannetti N., Verma S., Jian Z., Gomez Mesa J. E., Spinar J., Bohm M., Merkely B., Chopra V., Senni M., Taddi S., Tsutsui H., Chuquiure E., La Rocca H. P. B., Ponikowski P., Vinereanu D., Sim D., Choi D. -J., Juanatey J. R. G., Squire I., Januzzi J., Pina I., Pocock S. J., Carson P., Doehner W., Miller A., Haas M., Pehrson S., Komajda M., Anand I., Teerlink J., Rabinstein A., Steiner T., Kamel H., Tsivgoulis G., Lewis J., Freston J., Kaplowitz N., Mann J., Petrie M., Bernstein R., Cheung A., Green J., Kaul S., Ping C. L. S., Lip G., Marx N., McCullough P., Mehta C., Rosenstock J., Sattar N., Scirica B., Wanner C., Welty F. K., Parhofer K. G., Clayton T., Pedersen T. R., Lees K. R., Konstam M. A., Greenberg B., Palmer M., Anker, S, Butler, J, Filippatos, G, Jamal, W, Salsali, A, Schnee, J, Kimura, K, Zeller, C, George, J, Brueckmann, M, Zannad, F, Packer, M, Perrone, S, Nicholls, S, Janssens, S, Bocchi, E, Giannetti, N, Verma, S, Jian, Z, Gomez Mesa, J, Spinar, J, Bohm, M, Merkely, B, Chopra, V, Senni, M, Taddi, S, Tsutsui, H, Chuquiure, E, La Rocca, H, Ponikowski, P, Vinereanu, D, Sim, D, Choi, D, Juanatey, J, Squire, I, Januzzi, J, Pina, I, Pocock, S, Carson, P, Doehner, W, Miller, A, Haas, M, Pehrson, S, Komajda, M, Anand, I, Teerlink, J, Rabinstein, A, Steiner, T, Kamel, H, Tsivgoulis, G, Lewis, J, Freston, J, Kaplowitz, N, Mann, J, Petrie, M, Bernstein, R, Cheung, A, Green, J, Kaul, S, Ping, C, Lip, G, Marx, N, Mccullough, P, Mehta, C, Rosenstock, J, Sattar, N, Scirica, B, Wanner, C, Welty, F, Parhofer, K, Clayton, T, Pedersen, T, Lees, K, Konstam, M, Greenberg, B, Palmer, M, Anker S. D., Butler J., Filippatos G. S., Jamal W., Salsali A., Schnee J., Kimura K., Zeller C., George J., Brueckmann M., Zannad F., Packer M., Perrone S., Nicholls S., Janssens S., Bocchi E., Giannetti N., Verma S., Jian Z., Gomez Mesa J. E., Spinar J., Bohm M., Merkely B., Chopra V., Senni M., Taddi S., Tsutsui H., Chuquiure E., La Rocca H. P. B., Ponikowski P., Vinereanu D., Sim D., Choi D. -J., Juanatey J. R. G., Squire I., Januzzi J., Pina I., Pocock S. J., Carson P., Doehner W., Miller A., Haas M., Pehrson S., Komajda M., Anand I., Teerlink J., Rabinstein A., Steiner T., Kamel H., Tsivgoulis G., Lewis J., Freston J., Kaplowitz N., Mann J., Petrie M., Bernstein R., Cheung A., Green J., Kaul S., Ping C. L. S., Lip G., Marx N., McCullough P., Mehta C., Rosenstock J., Sattar N., Scirica B., Wanner C., Welty F. K., Parhofer K. G., Clayton T., Pedersen T. R., Lees K. R., Konstam M. A., Greenberg B., and Palmer M.

Abstract

Background: The principal biological processes that characterize heart failure with a preserved ejection fraction (HFpEF) are systemic inflammation, epicardial adipose tissue accumulation, coronary microcirculatory rarefaction, myocardial fibrosis and vascular stiffness; the resulting impairment of left ventricular and aortic distensibility (especially when accompanied by impaired glomerular function and sodium retention) causes increases in cardiac filling pressures and exertional dyspnoea despite the relative preservation of left ventricular ejection fraction. Independently of their actions on blood glucose, sodium–glucose co-transporter 2 (SGLT2) inhibitors exert a broad range of biological effects (including actions to inhibit cardiac inflammation and fibrosis, antagonize sodium retention and improve glomerular function) that can ameliorate the pathophysiological derangements in HFpEF. Such SGLT2 inhibitors exert favourable effects in experimental models of HFpEF and have been found in large-scale trials to reduce the risk for serious heart failure events in patients with type 2 diabetes, many of whom were retrospectively identified as having HFpEF. Study design: The EMPEROR-Preserved Trial is enrolling ≈5750 patients with HFpEF (ejection fraction >40%), with and without type 2 diabetes, who are randomized to receive placebo or empagliflozin 10 mg/day, which is added to all appropriate treatments for HFpEF and co-morbidities. Study aims: The primary endpoint is the time-to-first-event analysis of the combined risk for cardiovascular death or hospitalization for heart failure. The trial will also evaluate the effects of empagliflozin on renal function, cardiovascular death,. all-cause mortality and recurrent hospitalization events, and will assess a wide range of biomarkers that reflect important pathophysiological mechanisms that may drive the evolution of HFpEF. The EMPEROR-Preserved Trial is well positioned to determine if empagliflozin can have a meaningfu

Published
2019

4. Ferric carboxymaltose in patients with heart failure and iron deficiency

Author

Anker, S D, Comin Colet, J, Filippatos, G, Willenheimer, R, Dickstein, K, Drexler, H, Lüscher, T F, Bart, B, Banasiak, W, Niegowska, J, Kirwan, B A, Mori, C, von Eisenhart Rothe, B, Pocock, S J, Poole-Wilson, P A, Ponikowski, P, Anker, S D, Comin Colet, J, Filippatos, G, Willenheimer, R, Dickstein, K, Drexler, H, Lüscher, T F, Bart, B, Banasiak, W, Niegowska, J, Kirwan, B A, Mori, C, von Eisenhart Rothe, B, Pocock, S J, Poole-Wilson, P A, and Ponikowski, P

Abstract

BACKGROUND: Iron deficiency may impair aerobic performance. This study aimed to determine whether treatment with intravenous iron (ferric carboxymaltose) would improve symptoms in patients who had heart failure, reduced left ventricular ejection fraction, and iron deficiency, either with or without anemia. METHODS: We enrolled 459 patients with chronic heart failure of New York Heart Association (NYHA) functional class II or III, a left ventricular ejection fraction of 40% or less (for patients with NYHA class II) or 45% or less (for NYHA class III), iron deficiency (ferritin level <100 microg per liter or between 100 and 299 microg per liter, if the transferrin saturation was <20%), and a hemoglobin level of 95 to 135 g per liter. Patients were randomly assigned, in a 2:1 ratio, to receive 200 mg of intravenous iron (ferric carboxymaltose) or saline (placebo). The primary end points were the self-reported Patient Global Assessment and NYHA functional class, both at week 24. Secondary end points included the distance walked in 6 minutes and the health-related quality of life. RESULTS: Among the patients receiving ferric carboxymaltose, 50% reported being much or moderately improved, as compared with 28% of patients receiving placebo, according to the Patient Global Assessment (odds ratio for improvement, 2.51; 95% confidence interval [CI], 1.75 to 3.61). Among the patients assigned to ferric carboxymaltose, 47% had an NYHA functional class I or II at week 24, as compared with 30% of patients assigned to placebo (odds ratio for improvement by one class, 2.40; 95% CI, 1.55 to 3.71). Results were similar in patients with anemia and those without anemia. Significant improvements were seen with ferric carboxymaltose in the distance on the 6-minute walk test and quality-of-life assessments. The rates of death, adverse events, and serious adverse events were similar in the two study groups. CONCLUSIONS: Treatment with intravenous ferric carboxymaltose in patients with chro

Published
2009

5. Lead Exposure and Child Development: An International Assessment

Author

Ahmedi, G., Ashby, Paul David, Baghurst, P.A., Beese, I, BELL, A, Bellinger, D.C, Belmont, L, Berger, O, Bergoni, M, Bier, M, Borella, P, BORNSCHEIN, Robert L, Bozovic, R, Bratel, J, Brittenham, G, Brockhaus, A, Bushnell, L, Campagna, R, CARTER, C, Catelli, D, Cavazutti, G B, Cluydts, Raymond, Colakovic, B, Collet, W, Cookman, G, Cooney, G, Cory-Slechta, D C, Davis, J M, Delves, T, Dietrich, K N, Emmern, S, Ernhart, C B, Ewert, T, Fantuzzi, G, Fulton, M, Gashi, E, Goldberg, A, Grandjean, Philippe, Grant, Lester D, Graziano, J, Greenland, R, Grote, J, Hamlin, M, Hammond, Paul B, Hansen, O N, Hargreaves, E, Harvey, P, Hatzakis, A, Haxhiu, R, Hennekes, R, Hepburn, W, Hidalgo, H, Hunter, J, Hunter, R, Kalandidi, A, Katsouyanni, K, Kazantzis, G, Keane, G, King, W, Kline, J, Kokkevi, A, Koutselinis, A, Krafft, K, Krämer, U, Krause, C, Kumar, R, Lansdown, R, Laxen, D P, Lenaerts, C, Leviton, A, Lilienthal, H, Loiacono, N, Lyngbye, T, Maravelias, C, Marler, M, McBride, W, J McMichael, A, Mehmetti, A, Mendes, C, Mitchell, T, Montorsi, R, Moore, Michael.M, Morgan, J, Morrow-Tlulak, M, Muddiman, D, Munoz, C, Mushak, Paul, Murphy, M, Needleman, Herbert L, Nenezic, D, Steenhout, Anne, Otto, D, Pelling, D, Pocock, S J, Popovac, D, Raab, G M, Rabinowitz, Michael, Radovic, L, Rajovic, B, Regan, C, Rice, Deborah C, Roberts, R, Ahmedi, G., Ashby, Paul David, Baghurst, P.A., Beese, I, BELL, A, Bellinger, D.C, Belmont, L, Berger, O, Bergoni, M, Bier, M, Borella, P, BORNSCHEIN, Robert L, Bozovic, R, Bratel, J, Brittenham, G, Brockhaus, A, Bushnell, L, Campagna, R, CARTER, C, Catelli, D, Cavazutti, G B, Cluydts, Raymond, Colakovic, B, Collet, W, Cookman, G, Cooney, G, Cory-Slechta, D C, Davis, J M, Delves, T, Dietrich, K N, Emmern, S, Ernhart, C B, Ewert, T, Fantuzzi, G, Fulton, M, Gashi, E, Goldberg, A, Grandjean, Philippe, Grant, Lester D, Graziano, J, Greenland, R, Grote, J, Hamlin, M, Hammond, Paul B, Hansen, O N, Hargreaves, E, Harvey, P, Hatzakis, A, Haxhiu, R, Hennekes, R, Hepburn, W, Hidalgo, H, Hunter, J, Hunter, R, Kalandidi, A, Katsouyanni, K, Kazantzis, G, Keane, G, King, W, Kline, J, Kokkevi, A, Koutselinis, A, Krafft, K, Krämer, U, Krause, C, Kumar, R, Lansdown, R, Laxen, D P, Lenaerts, C, Leviton, A, Lilienthal, H, Loiacono, N, Lyngbye, T, Maravelias, C, Marler, M, McBride, W, J McMichael, A, Mehmetti, A, Mendes, C, Mitchell, T, Montorsi, R, Moore, Michael.M, Morgan, J, Morrow-Tlulak, M, Muddiman, D, Munoz, C, Mushak, Paul, Murphy, M, Needleman, Herbert L, Nenezic, D, Steenhout, Anne, Otto, D, Pelling, D, Pocock, S J, Popovac, D, Raab, G M, Rabinowitz, Michael, Radovic, L, Rajovic, B, Regan, C, Rice, Deborah C, and Roberts, R

Abstract

0, European Commission and US.Environmental Protection Agency ;Published for the Commission of the European Communities and the U.S. Environmental Protection Agency (M. Smith, L. Grant ,A. Sors, Editors), info:eu-repo/semantics/published

Published
1989

6. Analysis of repeated measures in clinical trials using summary statistics

Author

Frison, Lars Johan and Pocock, S. J.

Subjects
610, Medicine
Abstract

This thesis is concerned with statistical methodology for randomized clinical trials with repeated measurements over time, as regards both data analysis and the implications for study design. The inherent within-subject dependencies for repeated measurements necessitate analyses that take account of their covariance structure. There exists a whole battery of methods for analysing repeated measures designs, ranging from very simple (e.g. separate t-tests at each time-point) to very complicated (e.g. multi-level models with arbitrary error structures), but I will focus on "the summary statistic approach" which has recently become increasingly popular. When interest centres around the average response to treatment over time, a logical choice of summary statistic is the mean of each subject's post-randomisation measurements, with appropriate adjustment for pre-treatment measurements. Among the class of "mean summary statistics" analysis of covariance (ANCOVA) is shown to be superior to its competitors. In particular, variance formulae are derived both under a general covariance structure and more specific cases (e.g. compound symmetry) , allowing direct comparisons of efficiency among different summary statistics and repeated measures designs. The importance of precise estimates of the pre-entry levels and the consequences for sample size requirements are emphasized. Some additional topics in relation to mean summary statistics, notably; the bias in estimation if pre-treatment means differ, the choice between additive or multiplicative models, and the summary statistic "area under the curve", are also investigated. For studies with restrictions on the range of baseline measurements the negative consequences incurred by "regression to the mean" are explored, especially regarding the variance for between-group comparisons. For a more general class of true treatment effects over time, the optimal linear summary statistic under any covariance structure is derived. Special interest is devoted to the case of linearly diverging mean treatment curves, where the optimal alternative to the comparison of slopes is defined. Asymptotic relative efficiencies are shown to be a useful tool when contrasting different designs and different summary statistics, both in the planning and reporting of repeated measures clinical trials. Finally, comparisons with other approaches are made, and recommendations given based on the need to balance theoretical considerations with practical matters.

Published
1994
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