Answer all questions in complete sentences and use proper APA citation when appropriate

PURPOSE OF RESEARCH AND THE ‘TREATMENT GAP’
1. State the purpose of the Cicero et al. (2018) research.  How is the 2018 paper an elaboration of the 2017 paper?
2. What is the ‘treatment gap’ that Cicero et al. (2018) mentions?  How did the ‘treatment gap’ manifest itself in Figure 1 (Cicero et al., 2018, p. 268)? 
HYPOTHESES
3.   If the main research hypothesis, in stylized form, for this trend study, is  
The annual percentage of SKIP respondents who indicated initiating regular opioid use with heroin exhibited a steadily increasing trend relative to the yearly percentage of those SKIP respondents who indicated initiating regular opioid use with prescription opioids over the 2005-2015 time period.
State the corresponding hypothesis.  
(HINT: dependent variable is “opioid of first regular use” with levels – heroin versus prescription opioids (hydrocodone and/or oxycodone) – and independent variable is time or more specifically, “year beginning regular use of opioid.”  Figure 1 may be helpful.) 
SAMPLING AND SURVEY
4.  As best you can, describe the sample design for the SKIP Program.   
      5.   What is the data-collection mode of administration used by SKIP Program?  What sort of 
            interview format was employed in SKIP Program survey?  (HINT: cf, Dixon et al., 2019, 
            pps. 215-216 and pps. 221- 229).
FINDING AND LIMITATIONS
       6.  Discuss the construction of variable named year beginning regular opioid use and how 
            Cicero et al. (2018) used it in the analysis of the SKIP Program data.
       7.  What are the study’s main findings?
       8.  What are the limitations of the study?  (HINT: Do not forget to consider the nature of the sample.)