Cross-sectional analysis of ethnic differences in fall prevalence in urban dwellers aged 55 years and over in the Malaysian Elders Longitudinal Research study by Alex, Deepa, Khor, Hui Min, Chin, Ai-Vyrn, Hairi, Noran Naqiah, Othman, Sajaratulnisah, Khoo, Selina, Kamaruzzaman, Shahrul Bahyah, Tan, Maw Pin