International Journal of Preventive Medicine (Int J Prev Med)2008-7802922018031318911891ENDepartment of Biostatistics and Epidemiology, Isfahan University of Medical Sciences, IsfahanModeling in Health Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, KermanNoncommunicable Diseases Research Center, Fasa University of Medical Sciences, FasaIsfahan Cancer Registry, Deputy of Health, Isfahan University of Medical Sciences, IsfahanMPH Department, Shiraz University of Medical Sciences, Shiraz20180313<p><span class="fontstyle0"><strong>Background</strong>: </span><span class="fontstyle2">Case fnding was improved to the population‑based method at the Isfahan Cancer Registry (ICR) during 2005–2008. However, its effects on the number of registered colorectal cancer (CRC) cases and patients’ age are not investigated. Therefore, present study designed to investigate the effect of that improvement on the trend of incidence of CRC, and age of CRC cases in ICR’s catchment area. </span></p><p><span class="fontstyle0"><strong>Methods</strong>: </span><span class="fontstyle2">Data from the ICR were retrieved by years for 2000–2011.<br />Annual age‑standardized incidence rates (ASRs), truncated ASRs and 95% confdence intervals (95% CIs) were estimated for both genders. Rates were standardized based on the 2000 world standard population. Trends were analyzed, and signifcant change‑points were identifed using Joinpoint Regression software. Age of CRC cases compared between periods before and after the improvement.</span></p><p><strong></strong><span class="fontstyle0"><strong>Results</strong>: </span><span class="fontstyle2">A total of 2902 CRC cases had been registered by ICR. Estimated ASRs (95% CI) for 2000 and 2011 were 3.47 (3.45, 3.50) and 10.22 (10.19, 1025) per 100,000 persons, respectively. Two signifcant change‑points were identifed (i.e., at 2003 and 2006). However, estimated average annual percent change was as 11. There was no signifcant difference between mean of patients’ age before and after the time of improvement (</span><span class="fontstyle3">P </span><span class="fontstyle2">= 0.88). </span></p><p><span class="fontstyle0"><strong>Conclusions</strong>: </span><span class="fontstyle2">Trends of incidence of CRC had been rising in central Iran for males and females, during 2000–2011. It seems that the estimated slope for this trend had been partially artifcial and signifcantly affected by the improvement of case‑fnding method. However, the improvement had no effect on the patients’ age.</span></p><p><span class="fontstyle2"><span class="fontstyle0"><strong>Keywords</strong>: </span><span class="fontstyle2">Colorectal cancer, incidence, Iran, neoplasm, trend</span> <br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;" /></span></p>http://ijpm.mui.ac.ir/index.php/ijpm/article/view/1891http://ijpm.mui.ac.ir/index.php/ijpm/article/download/1891/717717719