Bias in Prognostic Studies

In the evidence-based world every now and again you may come across a paper looking at prognosis. Such papers provide us information on understanding the natural history of a disease or condition, which may then be of use in understanding the nature of your specific patient’s illness (or of those patients who may later relate to the coursework you are teaching now). Knowing something about prognosis allows us to provide information to the patient about predicted outcomes of treatment, and for some conditions (such as, say, the common cold), we know a great deal. Conditions such as back pain are less well understood and therefore rife for discussion in a prognostic paper. But there are several kinds of bias which affect prognostic studies. These include:

Lead Time Bias: this occurs when earlier results related to diagnosis of a condition suggest a treatment effect even though the patient has not, for example, lived any longer. In reviewing studies of prognosis, we need to ensure that our inception cohort had a clearly defined inception point so that they all have the same starting point. Look to see that this is presented in the methods section.

Centripetal Bias: This occurs when a referral center has such a good reputation that it attracts people from outside its geographic location. This then affects the characteristics of the patients that center sees, since, for example, only those who can afford to travel there will be included in an analysis of the patients being seen. Effects or poverty would then be taken out of understanding how this disease progresses.

Popularity Bias: This happens when people with certain specific diagnoses are treated differently than those with other diagnoses or conditions. This may affect the patient flow in a tertiary care center known for its management of that specific condition, affecting the nature of the patients they then see and making them not reflective of the condition at it typically presents in a population.

Referral Bias: This occurs when a select group of patients is referred for study. The problem here is that this leads to that sample not being random or even a reasonable sample of the condition of interest.

Diagnostic Access Bias: If your starting point for conducting a prognostic study requires access to, say, an MRI imaging center, does your community even have one? Does each potential participant in the study have equal access to such a center? Some require referral and some require lengthy waits. This may affect the types of patient seen, making them atypical of the condition of interest.

Diagnostic Suspicion Bias: If the physician can identify the group assignment of a patient, he or she may treat that patient differently.

Expectation Bias: This occurs when a physician second-guesses what is happening in a trial due to prior knowledge he or she may have. The more information about each patient we have, the more our expectations may influence what we do and how we treat the patient, affecting prognosis.

These are sources of error in prognostic studies you should be aware of. Prognostic studies are not common in chiropractic, but are likely to occur in the future.

A few youtube clips that may help you understand EBCP concepts better

1. Risk:
http://www.youtube.com/watch?v=4LMTnLGwoF4
This is a nice little introduction to the concept of risk in medical literature. The author uses a simulated study to help illustrate concepts here.

2. Confidence Intervals:
http://www.youtube.com/watch?v=Hn6C21GC0vA&feature=related And here is a presentation which clarifies understanding of confidence intervals, another key concept in reading and interpreting medical literature.

3. Sample Size Calculation:
http://www.youtube.com/watch?v=HuGl50C8Q30&feature=related
Here the idea is to know how many subjects you need in a study to be able to achieve statistical significance.

4. Regression Analysis:
http://www.youtube.com/watch?v=JPjW2HPTaEw&feature=related
This is a common procedure used in statistics but not one everyone necessarily understands. This little clip does a nice job of explaining what this is.

5. Evidence-Based Medicine 1:
http://www.youtube.com/watch?v=QsIYwWwi_r4
An introduction to the topic, looking at critical appraisal.

6. Evidence-Based Practice: http://www.youtube.com/watchv=SWMjkxNpl6k&feature=related
This is about the real world applications of EBCP.

7. Research Methods:
http://www.youtube.com/watch?v=0FyCTupSdXM
A primer on beginning research.

Beyond this, so much more exists on youtube that can help explain concpets related to evidence-based practice, to teaching effectiveness and to scholarship. Poke around, and enter what I have called a "youtube fugue..."

Asking and Answering Questions Effectively in a Public Forum

The latest issue of the Journal of the American Medical Writers Association has a very interesting article about how to ask effective questions in public forms, and how to provide effective answers in return (1). It notes that often we are asked to sit though meetings and programs where we bemoan the fact that audience members ask long and seemingly pointless questions and in response receive even longer and less meaningful answers. We have all seen this happen, and we all sit and try not to squirm when it does. Beyond our discomfort, however, is a more important point: there is supposed to be a successful exchange of information and it has not occurred. Similar to writing, we need to communicate effectively. Krumm’s article provides an overview on making that happen. He provides an overview of 3 related topics in doing so.

First, he brings up the issue of understanding the different types of question. Krumm defines 3 types of questions one may see in a scientific setting. (1) The first is the Specific Question. These are questions which require a categorical answer, such as either yes or no, or a factual answer (and for whom the question usually starts with a wh, such as what, who, where, etc.). (2) Second is the Leading Question. This is an open-ended question requiring an element of analysis, synthesis or evaluation, and they require answers with more in-depth analysis and interpretation. (3) Finally, there is the Presupposition Question. These are questions with assumptions behind them, often critical in nature, and often begin with the word why. These often appear to be, and are, confrontational.

He then looks at asking effective questions. He suggests the following. (1) First, think about the question. Identify what it is you wish to know- broad information or specific. (2) Ask a precise question. This does not mean it must be short, but that it is formulated clearly so that the audience and the presenter easily understand it. (3) Stick to the topic at hand. Make sure your question is related to the discussion at hand. Do not introduce tangential topics. (4) Ask 1 question at a time. Too many questions can make it hard for the presenter to know how to answer and for the audience to follow. If you need to, ask if you can ask a follow-up question. (5) Be careful about “why” questions. These are seen as accusatory and put the presenter on the defensive. (6) Ask your question politely. You should never be rude or confrontational. This is also important when a presenter may have given incorrect information. Follow the Golden Rule. (7) Conversely, do not be overly complimentary; there is no need for a constant stream of praise to a presenter.

For those now in position to answer properly asked questions, Krumm suggests this: (1) Rehearse answers to obvious question. You know what you will be presenting, so anticipate the question you will get and be ready to answer them. (2) Clarify the rules (where appropriate). Let people know when and how you will answer questions. (3) Listen to the question and do not interrupt. Listening is a key skill, and don’t barge in out of impatience. (4) Repeat the question. Not everyone will have heard it. (5) Ask for clarification when necessary. You can politely ask when you are unclear as to what you are being asked. (6) Be honest. If you don’t know the answer, say so. (7) Give short and precise answers. Stick to the point, and remember others want to ask questions as well. (8) Don’t be defensive if the questions are hostile. This is hard to remember, but you can best defuse anger with calm. Remain courteous.

Note: I will be gone for much of next week, and will post again upon my return, May 16. Until then.

References
1. Krumm P. How to ask effective questions and provide effective answers in a public form. AMWA J 2011;26:21-22

A Few New Articles of Note

1. White MR, Jacobson IG, Smith B, Wells TS, Gacksetter G, Boyko EJ, Smith TC and the Millenium Cohort Study Team. Health care utilization among complementary and alternative medicine users in a large military cohort. BMC Compl Alternative Med 2011;11:27 doi:10.1186/1472-6882-11-27

ABSTRACT
Background: Complementary and Alternative Medicine use and how it impacts health care utilization in the United States Military is not well documented. Using data from the Millennium Cohort Study we describe the characteristics of CAM users in a large military population and document their health care needs over a 12-month period. The aim of this study was to determine if CAM users are requiring more physician-based medical services than users of conventional medicine.
Methods: Inpatient and outpatient medical services were documented over a 12-month period for 44,287 participants from the Millennium Cohort Study. Equal access to medical services was available to anyone needing medical care during this study period. The number and types of medical visits were compared between CAM and non-CAM users. Chi square test and multivariable logistic regression was applied for the analysis.
Results: Of the 44,287 participants, 39% reported using at least one CAM therapy, and 61% reported not using any CAM therapies. Those individuals reporting CAM use accounted for 45.1% of outpatient care and 44.8% of inpatient care. Individuals reporting one or more health conditions were 15% more likely to report CAM use than non-CAM users and 19% more likely to report CAM use if reporting one or more health symptoms. The unadjusted odds ratio for hospitalizations in CAM users compared to non-CAM users was 1.29 (95% CI: 1.16-1.43). The mean number of days receiving outpatient care for CAM users was 7.0 days and 5.9 days for non-CAM users (p < 0.001).
Conclusions: Our study found those who report CAM use were requiring more physician-based medical services than users of conventional medicine. This appears to be primarily the result of an increase in the number of health conditions and symptoms reported by CAM users.

2. Dizon JMR, Grimmer-Somers K, Kumar S. Study protocol. Effectiveness of the tailored EBP training program for Filipino physiotherapists: A randomised controlled trial. BMC Med Educ 2011;11:14 doi:10.1186/1472-6920-11-14

ABSTRACT
Background: Evidence implementation continues to challenge health professionals most especially those from developing countries. Filipino physiotherapists represent a group of health professionals in a developing country who by tradition and historical practice, take direction from a doctor, on treatment options. Lack of autonomy in decision-making challenges their capacity to deliver evidence-based care. However, this scenario should not limit them from updating and up-skilling themselves on evidence- based practice (EBP). EBP training tailored to their needs and practice was developed to address this gap. This study will be conducted to assess the effectiveness of a tailored EBP-training program for Filipino physiotherapists, in improving knowledge, skills, attitudes and behaviour to EBP. Participation in this program aims to improve capacity to EBP and engage with referring doctors to determine the most effective treatments for their patients.
Methods: A double blind randomised controlled trial, assessing the effectiveness of the EBP training intervention, compared with a waitlist control, will be conducted. An adequately powered sample of 54 physiotherapists from the Philippines will be recruited and randomly allocated to EBP intervention or waitlist control. Intervention: The EBP program for Filipino physiotherapists is a one-day program on EBP principles and techniques, delivered using effective adult education strategies. It consists of lectures and practical workshops. A novel component in this program is the specially-developed recommendation form, which participants can use after completing their training, to assist them to negotiate with referring doctors regarding evidence-based treatment choices for their patients. Pre and post measures of EBP knowledge, skills and attitudes will be assessed in both groups using the Adapted Fresno Test and the Questions to EBP attitudes. Behaviour to EBP will be measured using activity diaries for a period of three months.
Discussion: Should the EBP-training program be found to be effective in improving EBP-uptake in Filipino physiotherapists, it will form the basis of a much needed national intervention which is contextually appropriate to Filipino physiotherapists. It will therefore form the genesis for a model for building EBP capacity of other health professionals in the Philippines as well as physiotherapists in developing countries. Trial Registration: Current Controlled Trials: ISRCTN74485061

3. Souba WW. The Being of Leadership. Phil Ethics Humanities Med 2011;6:5 doi:10.1186/1747-5341-6-5

ABSTRACT
The ethical foundation of the medical profession, which values service above reward and holds the doctor-patient relationship as inviolable, continues to be challenged by the commercialization of health care. This article contends that a realigned leadership framework - one that distinguishes being a leader as the ontological basis for what leaders know, have, and do - is central to safeguarding medicine's ethical foundation. Four ontological pillars of leadership - awareness, commitment, integrity, and authenticity - are proposed as fundamental elements that anchor this foundation and the basic tenets of professionalism. Ontological leadership is shaped by and accessible through language; what health care leaders create in language "uses" them by providing a point of view (a context) within and from which they orient their conversations, decisions, and conduct such that they are ethically aligned and grounded. This contextual leadership framework exposes for us the limitations imposed by our mental maps, creating new opportunity sets for being and action (previously unavailable) that embody medicine's charter on professionalism. While this leadership methodology contrasts with the conventional results-oriented model where leading is generally equated with a successful clinical practice, a distinguished research program, or a promotion, it is not a replacement for it; indeed, results are essential for performance. Rather, being and action are interrelated and their correlated nature equips leaders with a framework for tackling health care's most complex problems in a manner that preserves medicine's venerable ethical heritage.

Prezi

Prezi (http://www.prezi.com) provides you with a new method of presenting information to your students. It can move slide-driven presentations in new and interesting directions, because it works in a less linear fashion than does a standard PowerPoint presentation. It is a new evolution of presentation technology. I recall sitting in class as a student as instructors brought acetate overheads into class. Initially, they might have actually copied or drawn their own information on those sheets, but as technology evolved they could copy a table, for example, from a book onto the acetate and at least provide a more professional0looking overhead. And then, as technology further evolved, digital PowerPoint slide began to replace the slide carousels we carried around, and the ease with which we could make our presentations increased. But despite the comfort we now have with the use of slide/presentation technology- most of us use PowerPoint to one degree or another- there are problems with that technology, leading some experts to refer to something called “death by PowerPoint.”

Prezi calls itself a digital storytelling tool. Unlike PowerPoint, which allows you to present in a linear fashion, Prezi uses content to create a storyline. You can zoom in and out and all around, working instead on a “whiteboard.” Perhaps it would be best to demonstrate. Go to this link and view the presentation there to see a prezi in action:
http://prezi.com/recyyolzxm3e/how-to-create-a-great-prezi/

I should note what prezi is not.

It is not a way to simply reuse your slides in a new format. It is not a program which requires you to have design skills. It is not like other presentation software, nor is it a way to make weak art look good. And it is not just for presentations. It can be used, for example, for concept mapping. I order to use it, you must sign up, but you can do so under their free plan, which gives you 100mb of storage and the ability to work online. There are paid options as well that allow you to make work private and to work offline, and they also offer reduced rates for educators. When you log onto the site, there are 3 tabs across the top: Your Prezis (where the ones you create are stored), Learn (for learning how to use the technology in more detail), and Explore (where you can see other’s prezis and participate in message boards).

To use this, you need to think differently about how you wish to present information. You will be telling a story, so you need to plan differently. You have to think visually and in terms of movement. But this is a novel and interesting technology and I wish to suggest you play with it a little bit and see how it might help you to reinforce learning.

Making a Distribution List in Outlook

A distribution list is a set of contacts that you create that makes it easy for you to send a broadcast email to that group of people. For example, if you have just been asked to chair a search committee for a new position at the college, you can set up a distribution list for that team- which you might name “New Position Team- to allow you to easily communicate with the members of the team but without the need to type in each individual name each time you wish to send the team a message. You can use this distribution list not just to send email messages, but also to set up meetings or tasks on Outlook. And setting up the list is relatively easy to do.

The distribution list will be stored in your Contacts folder. It is possible to make this a global account or a personal account, and we will do the later here (the former would make your list available to everyone in the college, which you probably don’t want to do). However, you can share your list with others by sending it to them, or having them copy if from a message you send out to others.

To create the list, first go to the File menu, point to New and then click on Distribution List. A box will open that asks you to give this list a name; name it so that you will recognize what that list is for. We might call it, again, “New Position Team.” On the Distribution List tab, please then click on Select Members. In the Address Book drop-down list, click on the address book that contains all the email addresses you want to include in your new distribution list; in this case, this will be the Global Address List. A Search Box will appear, and in it you should type the name of one of the people you wish to include. When that name finally appears, click it, and then click Members. Do this for each person you want to add to the list, and when done click OK.

The list is then saved in your Contacts folder under the name you gave it. When you wish to send an email to that list, all you need to do is to go to your Contacts folder, double click on the “card” for the distribution list, and when it opens, click on the tab on the ribbon on top that says Email. A blank email will open up already set to be sent to the members of the list. You can then type your message and just click to send.

You can add or delete members easily by opening the file as noted just above. You can delete a name by highlighting it and clicking Delete; you can add new names as you did before. This is an easy way to make sure you do not have to replicate or duplicate work.

The Hidden Curriculum

When we speak of the curriculum in a health care setting such as chiropractic education, we typically mean this to refer to what is more properly called the formal curriculum. This is the actual course of study offered by a chiropractic college, including its planned content, teaching, evaluation methods, syllabi, exercises, textbooks and other teaching aids, as used in classroom, laboratory or clinical settings (1). We might also add here our formal policy statements, competencies and so on.

But educators also understand that there is an informal curriculum as well; this refers to the teaching opportunities that come up over the course of the day that are unplanned but involve instruction. This can occur in a clinical setting (perhaps from a chance encounter with an unusual patient), but may also occur in faculty offices or hallway interactions where a teacher has a chance to interact with a student. And again, this informal curriculum supports what teachers feel students should be learning through the formal program, as well as in terms of appropriate skills and values.

Finally, there is the hidden curriculum, which includes “the ideological and subliminal messages of both the formal and informal curricula. The hidden curriculum can be both human and structural; that is, it can be transmitted through human behaviors and through the structures and practices of institutions” (2). The hidden curriculum was first defined by Philip Jackson, who did an ethnographic study on classroom teaching in 1968 (3). We can look at this as a “vast network of unwritten social and cultural values, rules, assumptions, and expectations.” And many feel this is as important as the formal curriculum in the process of educating students.

I find this example of the power of the hidden curriculum telling. Anderson notes this story concerning a colleague, that when he went to kindergarten he learned a whole set of facts he had not known before. He learned that he was fat, which he had not known before. He learned he was slower than his friends at almost everything he did. And he learned he was poor. And this is what he remembered many years later about this time in kindergarten (4).

It is important to note that everyone in our institution participates in the hidden curriculum- we all influence our students in ways we cannot know or predict; for example, in how we respond to a challenging question in class, or how we interact with a student who visits us in our office, or how we comment on a new initiative that the college has just advanced. Students will learn by observing us; this is also a part of professionalizing them to life as a physician. Let me ask: what are the unspoken messages within each of our academic departments, between administration and faculty, between faculty and students, and between clinic and academic teachers? Are we seen as treating everyone with respect? Whose voices are heard more than others, and why? As Alexander notes, the hidden curriculum supersedes the lecture series, and it starts long before classes start while not ending when classes end.

What is important for all of us to realize is that the hidden curriculum should be harmonious with the formal curriculum; one way of looking at this is from the perspective of “walking the walk and talking the talk.” What does it say for one of us to ask that we treat people with courtesy in the classroom but then have no time or patience for a student who seeks us in the office? We all come into contact with people, and we need to think about how our behavior, our words and our actions influence those around us. This is more powerful than we might realize.

References
1. Pinar W. Understanding curriculum. New York, NY; Peter Lang 1995
2. Wear D, Skillicom J. Hidden in plain sight: the formal, informal, and hidden curriculum of a psychiatry clerkship. Acad Med 2009;84:451-457
3. Jackson P. Life in classrooms. New York, NY; Holt, Rinehart and Winston, 1974
4. Anderson DJ. The hidden curriculum. Am J Roentgenol 1992;159:21-22