How Complete is the Swespine Register?

Abstract: In this paper we seek to answer the following question: How complete is the Swespineregister? In order to answer this question we believe that in a register that has the ambitionto follow-up patients throughout a specified period of time, two types of completeness haveto be defined: external and internal completeness. In our opinion, the correct assessment ofa register’s level of completeness, results in an increase in its credibility, revealing whetherthe register has met its desired level of quality.By defining the register’s target population we came to the conclusion that the methodused by Swespine to calculate external completeness yielded misleading results. We definedanother method of assessing external completeness and concluded that our questioncannot be answered.We have also found an appropriate way to calculate the register’s internal completenesslevel. Since the internal completeness decreases as the follow-up period increases, wesought to discover which groups of patients are more likely to respond to the follow-upquestionnaire. For this a Logistic Regression Method was applied.