Welcome back. Now, we're going to talk about some other considerations as you're starting your investigation. One of the questions that often comes up is the role of the laboratory. We have very sophisticated laboratory techniques now for both environmental and clinical kinds of testing, and oftentimes this becomes very useful adjunct tool or a centrally important tool if you're thinking about potential cluster investigations. One of the questions that comes up is, what is the role of the laboratory in terms of case definition? Ideally what you'd like to have is a definitive test which would tell you that the case is defined on the basis of a particular test. So, for example, if you're talking about particular kinds of cancers, there may be subtypes of cancers or even genetic markers, which would help you distinguish different kinds of cancers and identify those particular types or subtypes of cancers that are uniquely related to a particular exposure. This doesn't happen often but it can happen, and when it does, it makes it more appropriate to talk about the role of the laboratory as central in the investigation. This may not always be the case however. Sometimes you may find that laboratories are involved because you have people going to the doctor, and they're looking for together the patients or the people visiting the physician, and the physician also are looking for possible markers of either exposure or of disease. For example, there are a number of laboratories that we'll do very, very exhaustive suites of different kinds of biological tests, including a number of things that aren't necessarily known to be associated with a particular exposure, but they are tested for, and you may find that people are asking you about these when you're investigating one of these potential clusters. This becomes an important question because, as I mentioned, sometimes our biological understanding is incomplete, and these are for the opportunity to expand our knowledge. Generally speaking, this is ideally done when somebody is thinking that a marker could be potentially useful and test it rigorously. But it often happens that rather than that, you find that people are using tests for which there may not be a known association but are collected in the workup by the healthcare provider, and then when you start to think about are these useful tests, you may not necessarily know how to interpret them. This can be a challenge, but it's something that is important to think about as you engage in conversations with members of the community. Community members science is now, is a much bigger factor that can be used to be, and it can be very, very useful. Members of the community who live in the community know the community, are part of the community, are able to collect data, sometimes very sophisticated environmental data or human health effects data, and use that to help advance your knowledge. There are a number of cases now that people have been very involved in communities, where they will go out and do sampling. They will go out and collect data. These data have in some cases been the difference between calling something a cluster and not because the community members really understood their community, lived there and were able to go where they felt the exposures were taking place and identify problems. So, when we are talking about the general epidemiologic approaches to thinking about is this a cluster that we can identify, or is this something else, what we're basically asking is, what are the rates of the conditions in the people who are exposed with the rates of the condition than those who are not exposed to a particular agent or environment? We want in that comparison ideally to be able to do some statistical testing although as we will discuss now and in other lectures, that isn't always easy to do. As we think about putting this together, we have to be thinking about things like what is the time that we're interested in? What space or location or geography are we interested in? Are we interested in cases that are occurring now, new cases, or are we interested in historic cases over a period of time? We also want to think about what are people doing? This can be an important determinant of people's health because for people who are working, for who are raising families, other kinds of activity have very direct implications for their health, and we want to understand the role of that activity as you're thinking about is a particular health outcome associated uniquely or primarily with an exposure, that's an environmental exposure or there other things like personal activity that could play a role. We've talked a little bit about environmental measurements. It's important to think about those environmental measurements, and as I mentioned just a few slides ago, also to think about possible biological markers of exposure or disease and the extent to which we can use those either in a research setting or in a clinical setting to help distinguish people who have the condition and their exposure status from people who don't have the condition and their exposure status. Finally, you also have to think about issues like vulnerability based on things like pregnancy status. We know that in human development, fetal development goes through stages where you're maybe particularly susceptible or sensitive to different exposures at different times. So, these are all things you need to think about as you're thinking about exposure and the role that it may play in the health outcome of interest. How do you put all of this together? Really, it starts with formulating a hypothesis, but formulating hypothesis is not what comes first. What comes first is listening to the community and listening to the individual. Oftentimes when you go into a clinical encounter with a physician or a nurse, you are going to start describing your symptoms and the nurse or the clinician will be thinking, "That sounds like it could be the flu or some other condition." When we're talking with community members, it's not infrequent that we'll do the same thing. What's really important though is we not jump to conclusions and we not formulate those hypotheses too early. You may miss important aspects of what people are telling you because you're already starting to fit what you are thinking and what you are hearing into a framework rather than hearing completely what it is that people are telling you. So, you really do need to be thinking about disease processes and what might be leading to these particular conditions, but you shouldn't do it too early in the process, and you should always be receptive to the tone that people are using and the possibility that what they're telling you doesn't mesh with necessarily your preconceived notion of what's causing the problem. Two other things to think about, one is working with partners. We always work with multiple agencies and partners, and those include state and local health departments. It's very frequent in this work that we work with environment departments. Not infrequently we find ourselves working with and consulting with and talking with county councils or other governing agencies because they have a vested interest and a very real interest in the health of their community. As we've said over and over again, community advocacy organizations are critical to this process, and academic organizations can also play an important role. Then, finally, let's just talk a little bit about communication because as I've said over and over, communication is really critical at all stages. When you start the process, as you're moving through the process, there's nothing more certain to not only drive a wedge, but in many ways, make it more difficult to present findings, get information, do all the things that we're talking about. If you aren't communicating effectively at all stages, and if you don't start off with the assumption that you really want to share as much as possible with the community, you want to do non-judgmental listening, and you always want to make sure that your communication is two-way. There's nothing more certain to make a town meeting really, really tense and difficult than to be lecturing a group of people who lived in a place all their lives about what's happening in their community because you are the expert. So, listen, think about historical contexts beyond the questions for the questions that are being posed. Is there a history of trauma in this community? Is there a history of exposure to multiple agents that goes back decades or more? Is this a community that has been marginalized or that has some vulnerability or in which people have not been listened to or have been not able to control their own destinies? All of these things will affect your interaction with them and your ability to engage with them to try to answer their questions. This can happen in many, many different ways. It may be in written communications, it may be direct person-to-person communications, it may be through town halls, and there may be many ways in which you engage with communication, including social media and informal topics. At the end of the day, what you really want to be able to do is have a group of people or population. You want to have them feel as though they can talk to you, they can engage with you, that you're not prejudging the outcome, and that you're listening to what they're saying. That goes a long way towards establishing the kind of trust and working relationship and cooperative working relationship that can lead to a successful conclusion to your investigation.
