1
00:00:01,830 --> 00:00:03,810
Welcome to module nine.

2
00:00:03,810 --> 00:00:07,170
This module starts our discussion
of effect modification,

3
00:00:07,170 --> 00:00:08,670
which you may also have heard

4
00:00:08,670 --> 00:00:11,640
called interaction or moderation.

5
00:00:11,640 --> 00:00:14,670
And you will really hear those
terms used interchangeably

6
00:00:14,670 --> 00:00:15,630
throughout this class

7
00:00:15,630 --> 00:00:18,210
and in the field of public health.

8
00:00:18,210 --> 00:00:19,800
If we take a step back,

9
00:00:19,800 --> 00:00:22,650
we've been talking about
threats to internal validity

10
00:00:22,650 --> 00:00:26,220
and epi studies since
way back in module five.

11
00:00:26,220 --> 00:00:27,780
We started out with bias

12
00:00:27,780 --> 00:00:31,500
then we spent three modules
talking about confounding.

13
00:00:31,500 --> 00:00:33,270
We're going to spend
the next three modules

14
00:00:33,270 --> 00:00:37,680
talking about effect modification
using the same structure.

15
00:00:37,680 --> 00:00:39,720
We'll start here in module nine,

16
00:00:39,720 --> 00:00:41,100
going over the theoretical

17
00:00:41,100 --> 00:00:44,390
and conceptual framework
of effect modification.

18
00:00:44,390 --> 00:00:45,600
In the next module,

19
00:00:45,600 --> 00:00:48,030
we'll extend that into SPSS

20
00:00:48,030 --> 00:00:49,950
and the statistical techniques

21
00:00:49,950 --> 00:00:52,860
that you use to evaluate
effect modification.

22
00:00:52,860 --> 00:00:54,930
And then in module 11,

23
00:00:54,930 --> 00:00:56,580
we'll look at interpreting the results

24
00:00:56,580 --> 00:01:00,090
of effect modification in
the public health literature.

25
00:01:00,090 --> 00:01:03,930
Effect modification and
confounding are similar in concept,

26
00:01:03,930 --> 00:01:06,480
but they're actually very
different in practice.

27
00:01:06,480 --> 00:01:08,670
I recommend that you go back

28
00:01:08,670 --> 00:01:10,200
and review your epi one notes

29
00:01:10,200 --> 00:01:11,970
just to make sure that you feel solid

30
00:01:11,970 --> 00:01:14,250
about that basic difference.

31
00:01:14,250 --> 00:01:17,580
I've included the chapter from
your epi one gorgeous text

32
00:01:17,580 --> 00:01:19,440
on the interaction for reading

33
00:01:19,440 --> 00:01:21,810
before you get into your current text

34
00:01:21,810 --> 00:01:24,630
because I think it will
reinforce that solid grounding

35
00:01:24,630 --> 00:01:27,180
before you take a deeper
dive into the details

36
00:01:27,180 --> 00:01:30,090
and the analysis piece
in the current book.

37
00:01:30,090 --> 00:01:30,923
As always,

38
00:01:30,923 --> 00:01:33,240
please reach out to me or
your TA with questions.

39
00:01:33,240 --> 00:01:35,090
And we'll see you in the next module.