# Statistical methodology for ordinal data in meta-analysis

PhD Thesis

Hossain, Md. Belal. 2011. Statistical methodology for ordinal data in meta-analysis. PhD Thesis Doctor of Philosophy. University of Southern Queensland.
Title Statistical methodology for ordinal data in meta-analysis PhD Thesis Hossain, Md. Belal Khan, Shahjahan University of Southern Queensland Doctor of Philosophy 168 2011 Meta-analysis combines results from several independent studies. Different methods are available to carry out meta-analyses for binary and continuous outcomes. The effect measures used for binary outcomes are odds ratio (OR), relative risk (RR), risk difference (RD), arcsine difference (AS), hazard ratio (HR) etc. For continuous outcomes mean difference (MD) and standardisedmean difference (SMD) are used in meta-analysis. However, there are many medical and health studies in which the outcome variables are measured on an ordinal categorical scale with more than two categories. These categories arenon-numerically valued, usually levels. In a typical ordinal categorical data there may be L categories C1;C2; : : : ;CL (C1 is the best and CL the worst orvice versa) and J comparison groups G1;G2; : : : ;GJ . Hence the count data for such studies are represented by a J × L contingency table. As a special case when there are two comparison groups in randomised controlled trials(RCTs), we set a 2 × L contingency table. As a result, the ordinary OR, log OR or RR can not be used directly without splitting the 2 × L (L > 2) contingency table into 2 × 2 tables.Among other effect measures for ordinal data there are local and global odds ratios (Dale, 1984), cumulative odds ratios, continuation odds ratio (Agresti, 2010) etc. The local odds ratio measures local association for aspecific outcome category not for the whole study. The global odds ratio is a measure of ratios of the quadrant probabilities (J = L ≥ 4). Whereas in RCTs there are only two comparison groups (J = 2) namely the treatmentand control groups. The cumulative odds ratios provide a comparison of pairs of levels of the explanatory variable with respect to their entire conditional distribution of the dependent variable. As a result, these measures are notappropriate in meta-analysis with RCTs.The data from studies with several ordered categories are analysed by various methods in meta-analysis. Some methods require specic model assumptions while others collapse the 2 × L (L > 2) contingency table into 2 × 2 tables for measuring the effect size. For example, the proportionalodds model (Whitehead et al., 2001) requires a proportionality assumption and there is no well defined variance estimate of the pooled estimator for thesample size weight method (Edwardes and Baltzan, 2000) that uses general odds ratio (ORG) as an effect measure.Therefore we need a method in meta-analysis that can be used for estimating the effect size without any loss of information by merging categories and is not restricted to any model assumptions.We propose generalised odds ratio (GOR) as an effect measure for ordinal categorical outcomes in meta-analysis (Agresti, 1980). For confidence intervals (CI) of the individual study effects and meta-analysis we employ independent multinomial distribution approach. A general fixed and a random effects models are developed using GOR in meta-analysis for ordinal categorical outcomes.Heterogeneity is one of the most problematic aspects in many metaanalyses. We have demonstrated a method to remedy the problem of heterogeneity in meta-analysis for ordinal data. Following Saleh (2006) a quasiempirical Bayes method (QEBM) is developed using predicted generalised method identifies the extreme studies and improves the meta-analysis in the presence of heterogeneity. Three different meta-analyses on several studies with different degree of heterogeneity are presented. The first example is of individual patients data (IPD) on tacrine trials with Alzheimer's disease, the second example is of misoprostol trials with insignificant heterogeneity and the third example is from simulation studies with significant heterogeneity. The three examples clearly illustrate detailed implementation process and usefulness of the proposed method.We apply and compare GOR with OR as an effect measure for binary outcomes in meta-analysis. Three alternative methods for combining results from binary outcomes are presented for meta-analysis. The first method is a sample size weight method (Edwardes and Baltzan, 2000) for binary outcomesusing ORG. The other two methods employ GOR as an effect measure for binary outcomes in meta-analysis. We present results by analysing six RCTs from meta-analysis of D1 versus D2 gastrectomy for gastric adenocarcinoma(Memon et al., 2011).This study also proposes GOR as an effect measure and presents method in meta-analysis for latent continuous outcomes. GOR is simple and it has straightforward interpretation. It can be used for more than two treatmentgroups as well. Hence GOR is a very useful effect measure in meta-analysis not only for multilevel ordinal categorical outcomes but also for binary and latent continuous outcomes. meta-analysis; statistical methodology; ordinal data 320299. Clinical sciences not elsewhere classified Department of Mathematics and Computing

https://research.usq.edu.au/item/q12vz/statistical-methodology-for-ordinal-data-in-meta-analysis

###### Published Version
 Hossain_2011_whole.pdf File access level: Anyone

total views
• ##### 3
views this month

## Related outputs

##### Meta-analysis of early endoscopic retrograde cholangiopancreatography (ERCP) ± endoscopic sphincterotomy (ES) versus conservative management for gallstone pancreatitis (GSP)
Burstow, Matthew J., Yunus, Rossita M., Hossain, Md Belal, Khan, Shahjahan, Memon, Breda and Memon, Muhammed A.. 2015. "Meta-analysis of early endoscopic retrograde cholangiopancreatography (ERCP) ± endoscopic sphincterotomy (ES) versus conservative management for gallstone pancreatitis (GSP)." Surgical Laparoscopy, Endoscopy and Percutaneous Techniques. 25 (3), pp. 185-203. https://doi.org/10.1097/SLE.0000000000000142
##### Laparoscopic vs open repair for incisional hernia
Awaiz, Aiman, Rahman, Foyzur, Hossain, Md Belal, Yunus, Rossita Mohamad, Khan, Shahjahan, Memon, Breda and Memon, Muhammad Ashraf. 2014. "Laparoscopic vs open repair for incisional hernia." Ahmed, Munir (ed.) 13th Islamic Countries Conference on Statistical Sciences . Bogor, Indonesia 18 - 21 Dec 2014 Lahore, Pakistan.
##### Statistical meta-analysis for ordinal categorical data
Hossain, Md. Belal and Khan, Shahjahan. 2012. "Statistical meta-analysis for ordinal categorical data." Ahmed, Munir (ed.) 11th Islamic Countries Conference on Statistical Sciences. Lahore, Pakistan 19 - 22 Dec 2011 Lahore, Pakistan.
##### Meta-analysis of laparoscopic posterior and anterior fundoplication for gastro-oesophageal reflux disease
Subramanya, Manjunath S., Hossain, Md. Belal, Khan, Shahjahan, Memon, Breda and Memon, Muhammed Ashraf. 2010. "Meta-analysis of laparoscopic posterior and anterior fundoplication for gastro-oesophageal reflux disease." Amin, Zeinab and Hadi, Ali S. (ed.) 10th Islamic Countries Conference on Statistical Sciences. Cairo, Egypt 20 - 23 Dec 2009 Lahore, Pakistan.
##### Reply to comment to Meta-analysis and systematic review of laparoscopic versus open mesh repair for elective incisional hernia. Jensen K, Jorgensen LN
Awaiz, A., Rahman, F., Hossain, M. B., Yunus, R. M., Khan, S., Memon, B. and Memon, M. A.. 2015. "Reply to comment to Meta-analysis and systematic review of laparoscopic versus open mesh repair for elective incisional hernia. Jensen K, Jorgensen LN." Hernia. 19 (6), pp. 1027-1029. https://doi.org/10.1007/s10029-015-1432-z
##### Meta-analysis and systematic review of laparoscopic versus open mesh repair for elective incisional hernia
Awaiz, A., Rahman, F., Hossain, M. B., Yunus, R. M., Khan, S., Memon, B. and Memon, M. A.. 2015. "Meta-analysis and systematic review of laparoscopic versus open mesh repair for elective incisional hernia." Hernia. 19 (3), pp. 449-463. https://doi.org/10.1007/s10029-015-1351-z
##### Effect of timing of pharmaconutrition (immunonutrition) administration on outcomes of elective surgery for gastrointestinal malignancies: a systematic review and meta-analysis
Osland, Emma, Hossain, Md Belal, Khan, Shahjahan and Memon, Muhammed Ashraf. 2014. "Effect of timing of pharmaconutrition (immunonutrition) administration on outcomes of elective surgery for gastrointestinal malignancies: a systematic review and meta-analysis." Journal of Parenteral and Enteral Nutrition. 38 (1), pp. 53-69. https://doi.org/10.1177/0148607112474825
##### Laparoscopic anterior versus posterior fundoplication for gastro-esophageal reflux disease: a meta-analysis and systematic review
Memon, Muhammed Ashraf, Subramanya, Manjunath S., Hossain, Md Belal, Yunus, Rossita Mohamad, Khan, Shahjahan and Memon, Breda. 2015. "Laparoscopic anterior versus posterior fundoplication for gastro-esophageal reflux disease: a meta-analysis and systematic review." World Journal of Surgery. 39 (4), pp. 981-996. https://doi.org/10.1007/s00268-014-2889-0
##### Meta-analysis of D1 versus D2 gastrectomy for gastric adenocarcinoma
Memon, Muhammed Ashraf, Subramanya, Manjunath S., Khan, Shahjahan, Hossain, Md. Belal, Osland, Emma and Memon, Breda. 2011. "Meta-analysis of D1 versus D2 gastrectomy for gastric adenocarcinoma." Annals of Surgery. 253 (5), pp. 900-911. https://doi.org/10.1097/SLA.0b013e318212bff6
##### Meta-analysis of laparoscopic posterior and anterior fundoplication for gastro-oesophageal reflux disease
Subramanya, M. S., Hossain, M. B., Khan, S., Memon, B. and Memon, M. A.. 2010. "Meta-analysis of laparoscopic posterior and anterior fundoplication for gastro-oesophageal reflux disease." Li, Yan, Yang, Jiajia, Wen, Peng and Wu, Jinglong (ed.) 2010 IEEE/ICME International Conference on Complex Medical Engineering (ICME 2010). Gold Coast, Australia 13 - 15 Jul 2010 Piscataway, NJ. United States. https://doi.org/10.1109/ICCME.2010.5558829
##### Preliminary results of a meta-analysis evaluating the effect of immunonutrition on outcomes on outcomes of elective gastrointestinal surgery
Osland, Emma, Hossain, Md. Belal, Khan, Shahjahan and Memon, Muhammed A.. 2010. "Preliminary results of a meta-analysis evaluating the effect of immunonutrition on outcomes on outcomes of elective gastrointestinal surgery." Amin, Zeinab and Hadi, Ali S. (ed.) 10th Islamic Countries Conference on Statistical Sciences. Cairo, Egypt 20 - 23 Dec 2009 Lahore, Pakistan.
##### Meta-analysis of D1 versus D2 gastrectomy for gastric adenocarcinoma
Subramanya, Manjunath S., Hossain, Md. Belal, Khan, Shahjahan, Memon, Breda and Memon, Muhammed A.. 2010. "Meta-analysis of D1 versus D2 gastrectomy for gastric adenocarcinoma." Amin, Zeinab and Hadi, Ali S. (ed.) 10th Islamic Countries Conference on Statistical Sciences. Cairo, Egypt 20 - 23 Dec 2009 Lahore, Pakistan.