Struggling Readers Past Grade 3

I am struggling with the statistics that students that struggle with reading after the 3rd Grade will continue to struggle throughout school. I personally struggled with reading right into high school. I struggled especially in decoding words and definitely in comprehension (well pretty much all aspects of reading)! I resisted even trying to get better wanting everything in the world to avoid tasks that involved reading (especially in school). This is no longer the case. The only struggle I have now is with speed. So, is it cognitive development, emotional, psychological, or simply motivation (as in the circumstances of struggling readers...socioeconomic status, parents reading difficulties, family learning expectations, cultural influences, hearing impairments, underdeveloped of spoken English ...etc.) Or, is it an intrinsic motivating factor (likely the lack of and a lack commitment to lifelong learning) that enables some to go against these statistics.