Johann Tang
Tan Tock Seng Hospital
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Publication
Featured researches published by Johann Tang.
Journal of Medical Imaging and Radiation Oncology | 2008
Johann Tang; Thomas P. Shakespeare; Jiade Jay Lu; Yiong Huak Chan; Khai Mun Lee; Wong Lc; Rahul K. Mukherjee; Michael Back
The palliative radiotherapeutic management of unresectable non‐small‐cell lung cancer is controversial, with various fractionation (Fx) schedules available. We aimed to determine patient’s choice of Fx schedule after involvement in a decision‐making process using a decision board. A decision board outlining the various advantages and disadvantages apparent in the Medical Research Council study of Fx schedules (17 Gy in two fractions vs 39 Gy in 13 fractions) was discussed with patients who met Medical Research Council eligibility criteria. Patients were then asked to indicate their preferred Fx schedules, reasons and their level of satisfaction with being involved in the decision‐making process. Radiation oncologists (RO) could prescribe radiotherapy schedules irrespective of patients’ preferences. Of 92 patients enrolled, 55% chose the longer schedule. English‐speaking patients were significantly more likely to choose the longer schedule (P = 0.02, 95% confidence interval: 1.2–7.6). Longer Fx was chosen because of longer survival (90%) and better local control (12%). Shorter Fx was chosen for shorter overall treatment duration (80%), cost (61%) and better symptom control (20%). In all, 56% of patients choosing the shorter schedule had their treatment altered by the treating RO, whereas only 4% of patients choosing longer Fx had their treatment altered (P < 0.001). Despite this, all (100%) patients were satisfied with being involved in the decision‐making process. The decision board was useful in aiding decision‐making, with both Fx schedules being acceptable to patients. Interestingly, despite the longer average survival associated with longer Fx, nearly half of the patients believed that this was not as important as a shorter duration of treatment and lower cost. Despite patients’ preferences, there were significant alterations of preferred schedules because of RO’s own biases.
Medical Decision Making | 2008
Thomas P. Shakespeare; Val Gebski; Johann Tang; Keith Lim; Jiade Jay Lu; Xiaojian Zhang; Guoliang Jiang
Background. The manner of presentation of research results may affect how clinicians interpret research and make clinical decisions. The authors evaluate whether the use of confidence levels improve research interpretation and decision making compared with P values and 95% confidence intervals. Methods. The 2 Presentation and Interpretation of Medical Research (PRIMER) studies were 3-arm randomized trials. PRIMER 1 presented results of 5 fictitious scenarios with P values (P), P plus 95% confidence intervals (P + CI), or P, CI, and confidence levels (P + CI + CL); PRIMER 2 compared P + CI + CL, P + CI, and P + CL. Clinicians were asked to identify the correct interpretation of scenarios in terms of statistical and clinical significance and then indicate the intended decision making in terms of treatment recommendation. Results. Seventy-five and 246 clinicians participated in PRIMER 1 and PRIMER 2, respectively. In PRIMER 1, P+CI+CL was superior to P + CI and P (P < 0.05); the latter 2 arms did not differ significantly. Decision making was not significantly different between arms. In PRIMER 2, P+CI+CL resulted in better interpretation than P + CI (P = 0.03), with no difference between P + CI and P + CL. In combined analysis, the odds of correct interpretation were higher for P+CI+CL than P+CI (odds ratio = 1.73, P=0.005, 95% CI= 1.19--2.52). Decision making was better for P + CI+ CL (P = 0.03). On multivariate analysis, the P + CI+ CL arm and clinicians with statistics training, not in private practice, or participating in PRIMER 1 had better interpretation. The P + CI+ CL arm was the only factor improving decision making. Conclusions. Presenting research with a combination of P values, confidence intervals, and confidence levels leads to better interpretation and decision making by clinicians.
International Journal of Radiation Oncology Biology Physics | 2004
Cheng Nang Leong; Thomas P. Shakespeare; Rahul K. Mukherjee; Michael Back; Khai Mun Lee; Jiade Jay Lu; Christopher J. Wynne; Keith Lim; Johann Tang; Xiaojian Zhang
International Journal of Radiation Oncology Biology Physics | 2006
Johann Tang; Michael Back; Rahul K. Mukherjee; Khai Mun Lee; Jiade Jay Lu; L. Wong; Thomas P. Shakespeare
Journal of Radiation Oncology | 2017
David Chia; Sarahatul B Yusoff; Desiree Chen; J. Tey; Johann Tang; Vicky Koh; Jiade J. Lu; Bok Ai Choo; Wee Yao Koh
International Journal of Radiation Oncology Biology Physics | 2012
S. Yusoff; David Chia; Johann Tang; J. Lu
Singapore Medical Journal | 2007
Thomas P. Shakespeare; Johann Tang; Shen L; Jiade Jay Lu; Rahul K. Mukherjee; Khai Mun Lee; Christopher J. Wynne; Michael Back
Journal of Medical Imaging and Radiation Oncology | 2005
Johann Tang; Michael Back; Thomas P. Shakespeare; Jiade Jay Lu; Rahul K. Mukherjee; Christopher J. Wynne; Liang S
Ejso | 2018
Caryn Wujanto; Liang Shen; David Sp. Tan; Yiat Horng Leong; Johann Tang; Vicky Koh
Brachytherapy | 2017
Vicky Koh; Bok Ai Choo; Khai Mun Lee; Teng Hwee Tan; Jen Hui Jeffrey Low; Soon Yau Joseph Ng; A. Ilancheran; Liang Shen; Johann Tang