01/17/05 14:10:21 malak1993 Logs in
01/17/05 14:11:29 malak1993 Logs Out
01/17/05 14:59:02 usmle_guy Logs in
01/17/05 14:59:03 usmle_guy Joins Subroom USMLE_Step_1
01/17/05 15:02:07 clover Logs in
01/17/05 15:02:07 clover Joins Subroom USMLE_Step_1
01/17/05 15:02:18 clover Leaves Subroom
01/17/05 15:02:53 clover: the usmle step 1 chat is in the step 1 chat room at 3 pm eastern....right?
01/17/05 15:02:58 clover Joins Subroom USMLE_Step_1
01/17/05 15:03:13 [USMLE_Step_1] usmle_guy: hi clover
01/17/05 15:03:28 [USMLE_Step_1] clover: hey usmle_guy
01/17/05 15:03:32 [USMLE_Step_1] clover: how are you?
01/17/05 15:03:43 [USMLE_Step_1] usmle_guy: good. how about you?
01/17/05 15:03:53 [USMLE_Step_1] clover: i'm good too. thanks.
01/17/05 15:04:12 [USMLE_Step_1] usmle_guy: did the time change for the chats?
01/17/05 15:04:26 [USMLE_Step_1] clover: not sure. haven't seen roxanita for a while
01/17/05 15:04:41 [USMLE_Step_1] usmle_guy: i tried to send her a PM and didnt get a reply yet
01/17/05 15:04:57 [USMLE_Step_1] clover: hope she is ok
01/17/05 15:05:10 [USMLE_Step_1] usmle_guy: me too. i'm worried about her
01/17/05 15:08:49 zoya Logs in
01/17/05 15:08:50 zoya Joins Subroom USMLE_Step_1
01/17/05 15:09:04 mick Logs in
01/17/05 15:09:11 mick Joins Subroom USMLE_Step_1
01/17/05 15:09:12 [USMLE_Step_1] zoya: hi
01/17/05 15:09:18 [USMLE_Step_1] usmle_guy: hi zoya
01/17/05 15:09:25 [USMLE_Step_1] usmle_guy: how are you?
01/17/05 15:09:36 [USMLE_Step_1] clover: hello zoya and mick
01/17/05 15:09:50 [USMLE_Step_1] zoya: good; how are you?
01/17/05 15:10:00 [USMLE_Step_1] mick: hi everyone
01/17/05 15:10:08 [USMLE_Step_1] usmle_guy: good
01/17/05 15:10:16 [USMLE_Step_1] usmle_guy: hi mick
01/17/05 15:10:50 [USMLE_Step_1] zoya: have you heard anything from rox?
01/17/05 15:10:54 [USMLE_Step_1] mick: new here. mind if i just observe today?
01/17/05 15:11:12 [USMLE_Step_1] usmle_guy: i tried to write to her, but she didn't reply
01/17/05 15:11:46 [USMLE_Step_1] zoya: oh
01/17/05 15:11:56 [USMLE_Step_1] clover: mick, feel free to observe or join in whenever you're ready. no rush
01/17/05 15:12:04 [USMLE_Step_1] mick: thanks
01/17/05 15:12:29 [USMLE_Step_1] zoya: sure
01/17/05 15:12:54 [USMLE_Step_1] zoya: so the chats are still on 3pm
01/17/05 15:13:05 [USMLE_Step_1] usmle_guy: i guess we should probably assume that she wont be here at this time at least. should we change the time or leave it as is, or keep trying to contact her?
01/17/05 15:13:56 [USMLE_Step_1] clover: i think the chats used to be at 8pm before and more people participated
01/17/05 15:14:19 [USMLE_Step_1] usmle_guy: night time is better for me personally, but i'll go with the majority
01/17/05 15:14:41 [USMLE_Step_1] zoya: i want to join the chats , but because of the timing most of the time i am not able to...
01/17/05 15:15:01 [USMLE_Step_1] usmle_guy: what is a good time for you zoya?
01/17/05 15:16:09 [USMLE_Step_1] zoya: any time after 6
01/17/05 15:17:25 [USMLE_Step_1] clover: sounds good to me. i think that 8 or 8:30 is better because some people are on the west coast
01/17/05 15:18:45 [USMLE_Step_1] usmle_guy: do you all want to try to change it to 8 pm?
01/17/05 15:18:55 [USMLE_Step_1] zoya: i wanted to ask rox first .............but i heard her father had an accident .....that might be the reason she is not able to join.
01/17/05 15:19:20 [USMLE_Step_1] usmle_guy: i hope he is ok.
01/17/05 15:19:28 [USMLE_Step_1] zoya: but if all of you think its ok to change the time then its fine with me
01/17/05 15:19:45 [USMLE_Step_1] zoya: me too
01/17/05 15:19:56 [USMLE_Step_1] usmle_guy: i wanted to ask rox first too, but we haven't been able to contact her for the past couple of weeks
01/17/05 15:20:12 zoya Logs Out
01/17/05 15:20:43 zoya Logs in
01/17/05 15:20:48 zoya Joins Subroom USMLE_Step_1
01/17/05 15:21:01 [USMLE_Step_1] usmle_guy: welcome back
01/17/05 15:21:12 [USMLE_Step_1] zoya: yeah
01/17/05 15:21:32 [USMLE_Step_1] zoya: but i missed what you were saying
01/17/05 15:21:46 [USMLE_Step_1] usmle_guy: ok, lets post something on the forum and see if we get a decent response
01/17/05 15:21:54 [USMLE_Step_1] usmle_guy: for the time change
01/17/05 15:22:02 [USMLE_Step_1] zoya: ok
01/17/05 15:22:25 [USMLE_Step_1] usmle_guy: since we're already here, we can go over todays topic
01/17/05 15:22:31 [USMLE_Step_1] clover: ok
01/17/05 15:22:46 [USMLE_Step_1] zoya: ok
01/17/05 15:22:53 [USMLE_Step_1] usmle_guy: Epidemiology Statistics
01/17/05 15:23:24 [USMLE_Step_1] usmle_guy: what is incidence vs prevalence?
01/17/05 15:23:50 zoya Logs Out
01/17/05 15:23:56 [USMLE_Step_1] clover: incidence are new events and prevalence are the total events
01/17/05 15:24:10 zoya Logs in
01/17/05 15:24:15 zoya Joins Subroom USMLE_Step_1
01/17/05 15:24:41 [USMLE_Step_1] usmle_guy: thats right. incidence=new, prevalence=all
01/17/05 15:25:13 [USMLE_Step_1] zoya: i keep getting disconected and missing the previous messages
01/17/05 15:25:50 [USMLE_Step_1] usmle_guy: the question was the difference between incidence and prevalence. answer was new vs all
01/17/05 15:26:03 [USMLE_Step_1] zoya: oh,thanks
01/17/05 15:26:10 [USMLE_Step_1] usmle_guy: what happens to incidence and prevalence in the following? new effective treatment initiated?
01/17/05 15:26:34 [USMLE_Step_1] zoya: prev goes down
01/17/05 15:26:40 [USMLE_Step_1] clover: incidence same prevalence goes down
01/17/05 15:26:51 [USMLE_Step_1] usmle_guy: yes, both right
01/17/05 15:26:51 [USMLE_Step_1] zoya: no change in incidence
01/17/05 15:27:08 [USMLE_Step_1] usmle_guy: new effective vaccine?
01/17/05 15:27:21 [USMLE_Step_1] clover: both go down
01/17/05 15:27:42 [USMLE_Step_1] zoya: both goes down
01/17/05 15:27:58 [USMLE_Step_1] usmle_guy: both correct again
01/17/05 15:28:01 [USMLE_Step_1] usmle_guy: number of persons dying from condition increase?
01/17/05 15:28:20 [USMLE_Step_1] clover: prevalence goes down. incidence same
01/17/05 15:28:41 [USMLE_Step_1] zoya: rt
01/17/05 15:28:58 [USMLE_Step_1] usmle_guy: correct
01/17/05 15:29:01 [USMLE_Step_1] usmle_guy: additional research dollars targeted to specific condition?
01/17/05 15:29:21 [USMLE_Step_1] zoya: no change in either
01/17/05 15:29:25 [USMLE_Step_1] clover: no change in either one...i think
01/17/05 15:29:33 [USMLE_Step_1] usmle_guy: thats right
01/17/05 15:29:53 [USMLE_Step_1] usmle_guy: behavioral risk factors reduced in population
01/17/05 15:30:06 [USMLE_Step_1] clover: both go down
01/17/05 15:30:15 [USMLE_Step_1] zoya: rt
01/17/05 15:30:24 bharatjoker Logs in
01/17/05 15:30:33 [USMLE_Step_1] usmle_guy: correct
01/17/05 15:31:01 bharatjoker Logs Out
01/17/05 15:31:17 [USMLE_Step_1] usmle_guy: contacts between infected and non-infected persons reduced for airborne infectous diseases? for non-infectious diseases? (separate questions)
01/17/05 15:32:01 [USMLE_Step_1] clover: for infectious then they would both go down. but if non infectious anyway, i dont think it would change
01/17/05 15:32:30 [USMLE_Step_1] zoya: rt
01/17/05 15:32:41 [USMLE_Step_1] usmle_guy: correct
01/17/05 15:33:02 [USMLE_Step_1] usmle_guy: long term survival rates for disease are increasing?
01/17/05 15:33:30 [USMLE_Step_1] clover: incidence is same and prevalence would go up....is that possible??
01/17/05 15:33:58 [USMLE_Step_1] zoya: prev inc but no change in incidence
01/17/05 15:34:24 [USMLE_Step_1] usmle_guy: this is the only one where you actually see the prevalence increasing because more people are living with the disease
01/17/05 15:34:47 [USMLE_Step_1] usmle_guy: that about covers incidence and prevalence
01/17/05 15:35:08 [USMLE_Step_1] clover: whats the formula for sensitivity?
01/17/05 15:35:15 [USMLE_Step_1] zoya: mortality rate refers to incidence /prevalance?
01/17/05 15:35:33 [USMLE_Step_1] usmle_guy: mortality refers to incidence only
01/17/05 15:35:41 [USMLE_Step_1] clover: incidence
01/17/05 15:35:41 [USMLE_Step_1] zoya: yes
01/17/05 15:36:10 [USMLE_Step_1] usmle_guy: sensitivity = TP/TP+FN
01/17/05 15:36:28 [USMLE_Step_1] zoya: tp/tp+fn
01/17/05 15:36:33 [USMLE_Step_1] clover: yes. what about for specificity?
01/17/05 15:36:50 [USMLE_Step_1] usmle_guy: TN/TN+FP
01/17/05 15:36:57 [USMLE_Step_1] zoya: tn/tn+fp
01/17/05 15:37:12 [USMLE_Step_1] clover: yes. what about positive predictive value?
01/17/05 15:37:26 [USMLE_Step_1] usmle_guy: TP/TP+FP
01/17/05 15:37:50 [USMLE_Step_1] zoya: tp?tp+fp
01/17/05 15:37:59 [USMLE_Step_1] clover: yes. what about negative predictive value?
01/17/05 15:38:10 [USMLE_Step_1] usmle_guy: TN/TN+FN
01/17/05 15:38:24 [USMLE_Step_1] zoya: tn/tn+fn
01/17/05 15:38:44 [USMLE_Step_1] clover: yes
01/17/05 15:39:05 [USMLE_Step_1] zoya: accuracy?
01/17/05 15:39:44 [USMLE_Step_1] usmle_guy: test measures what it was intended to measure
01/17/05 15:40:16 [USMLE_Step_1] clover: the bullseye on a target
01/17/05 15:40:39 [USMLE_Step_1] zoya: yes
01/17/05 15:40:51 [USMLE_Step_1] zoya: formulla?
01/17/05 15:41:06 [USMLE_Step_1] clover: if you hit the bullseye, its accurate. if you consistently hit the same group of shots outside of the bullseye, its reliable, but not accurate
01/17/05 15:41:18 [USMLE_Step_1] zoya: yes
01/17/05 15:41:50 [USMLE_Step_1] clover: formula for accuracy?? i didnt know there was one??
01/17/05 15:42:36 [USMLE_Step_1] usmle_guy: i dont know that one either
01/17/05 15:42:56 [USMLE_Step_1] zoya: tp+tn/tp+tn+fp+fn
01/17/05 15:43:22 [USMLE_Step_1] zoya: kap,page 7
01/17/05 15:43:44 [USMLE_Step_1] usmle_guy: oh, ok. i found it
01/17/05 15:44:05 [USMLE_Step_1] clover: thanks
01/17/05 15:44:28 [USMLE_Step_1] zoya: you are welcome
01/17/05 15:44:37 [USMLE_Step_1] clover: what is meant by condounding?
01/17/05 15:44:52 [USMLE_Step_1] usmle_guy: more than one explanation
01/17/05 15:45:15 [USMLE_Step_1] zoya: confounding?
01/17/05 15:47:52 [USMLE_Step_1] clover: yes, confounding means that many different explanations can explain the results. like obesity can be due to genetic factors, diet, lack of exercise. not any one cause, but many possible causes
01/17/05 15:48:34 [USMLE_Step_1] zoya: yes,nice example
01/17/05 15:49:31 mmw Logs in
01/17/05 15:49:32 mmw Joins Subroom USMLE_Step_1
01/17/05 15:49:38 [USMLE_Step_1] usmle_guy: when dealing with observational studies, which is for the present time (prevalence), which is for retrospective, and which is prospective? 3 different answers?
01/17/05 15:49:54 [USMLE_Step_1] usmle_guy: hi mmw. good to see you
01/17/05 15:50:01 [USMLE_Step_1] clover: hello mmw
01/17/05 15:50:07 [USMLE_Step_1] zoya: hi mmw
01/17/05 15:50:25 [USMLE_Step_1] mmw: hi usmle_guy clover zoya
01/17/05 15:50:34 [USMLE_Step_1] mmw: how r u all guys
01/17/05 15:50:35 [USMLE_Step_1] zoya: how are you doing/
01/17/05 15:51:00 [USMLE_Step_1] usmle_guy: good, how about you?
01/17/05 15:51:12 [USMLE_Step_1] mmw: better now but i have been checking this forum everyday and i could'nt find any of u
01/17/05 15:51:17 [USMLE_Step_1] mick: hi mmw
01/17/05 15:51:28 [USMLE_Step_1] mmw: hi mick
01/17/05 15:51:59 [USMLE_Step_1] usmle_guy: we were thinking about changing it to 8 pm instead because many of us have trouble making it at 3
01/17/05 15:52:21 [USMLE_Step_1] usmle_guy: would that time be ok with you?
01/17/05 15:52:24 [USMLE_Step_1] mmw: i did not study for nearly a week i just come and check u
01/17/05 15:52:35 [USMLE_Step_1] mmw: yes for me is ok for any time
01/17/05 15:53:15 [USMLE_Step_1] usmle_guy: i posted something in the forum so hopefully we'll be able to get it changed so that we can get the whole group going again
01/17/05 15:53:48 [USMLE_Step_1] mmw: if u come for everyday it's ok we can chat everyday what about for the others
01/17/05 15:53:49 [USMLE_Step_1] zoya: so what about tomorrow?
01/17/05 15:53:51 [USMLE_Step_1] mmw: yes
01/17/05 15:54:29 [USMLE_Step_1] usmle_guy: i hope everyone will read the forum by tomorrow. we can change it for tomorrow if everyone is ok with it
01/17/05 15:54:30 [USMLE_Step_1] mmw: what is the toopics and did u all finish patho?
01/17/05 15:54:49 [USMLE_Step_1] zoya: ok
01/17/05 15:55:03 [USMLE_Step_1] zoya: no .........ididn't
01/17/05 15:55:17 [USMLE_Step_1] mmw: for me ok
01/17/05 15:55:19 [USMLE_Step_1] usmle_guy: the topic for this week is behavioral. i guess we can go back to path after we finish the schedule so that we dont mess it up. what do you think?
01/17/05 15:55:35 [USMLE_Step_1] clover: ok for me too
01/17/05 15:55:37 [USMLE_Step_1] zoya: ok
01/17/05 15:55:40 [USMLE_Step_1] mmw: yeh
01/17/05 15:55:46 [USMLE_Step_1] mmw: good
01/17/05 15:56:00 [USMLE_Step_1] mick: i'm just ovserving, but i'll be here tomorrow at 8 if that is what is better for all
01/17/05 15:56:29 [USMLE_Step_1] mmw: what is the topic of ** for tomorrow?
01/17/05 15:56:29 [USMLE_Step_1] zoya: you are welcome mick
01/17/05 15:56:49 [USMLE_Step_1] usmle_guy: today is Epidemiology Statistics
01/17/05 15:56:51 [USMLE_Step_1] zoya: epidemiology and stat
01/17/05 15:56:55 tampa Logs in
01/17/05 15:57:04 [USMLE_Step_1] usmle_guy: tomorrow is Social Life in the US Substance Abuse Human Sexuality
01/17/05 15:57:17 saghar Logs in
01/17/05 15:57:23 mick Leaves Subroom
01/17/05 15:57:43 [USMLE_Step_1] mmw: i follow today with all of u cause i did'nt prepared for today what about tomorrow?
01/17/05 15:57:45 saghar Joins Subroom USMLE_Step_1
01/17/05 15:57:49 mick: if you are here for step 1, its in the step 1 room
01/17/05 15:57:52 tampa Logs Out
01/17/05 15:57:54 mick Joins Subroom USMLE_Step_1
01/17/05 15:57:56 [USMLE_Step_1] mmw: ok
01/17/05 15:58:18 [USMLE_Step_1] usmle_guy: hi saghar
01/17/05 15:58:22 [USMLE_Step_1] saghar: Hi
01/17/05 15:58:28 [USMLE_Step_1] clover: hello saghar
01/17/05 15:58:34 tampa Logs in
01/17/05 15:58:35 tampa Joins Subroom USMLE_Step_1
01/17/05 15:58:35 [USMLE_Step_1] saghar: Hi everybody
01/17/05 15:58:44 [USMLE_Step_1] mmw: hi
01/17/05 15:58:48 [USMLE_Step_1] mick: hi
01/17/05 15:58:52 [USMLE_Step_1] tampa: hello
01/17/05 15:58:55 [USMLE_Step_1] saghar: I thought the today's chat about **, isn't it?
01/17/05 15:59:03 [USMLE_Step_1] clover: hello tampa
01/17/05 15:59:07 [USMLE_Step_1] tampa: hi
01/17/05 15:59:09 [USMLE_Step_1] usmle_guy: hi tampa
01/17/05 15:59:29 [USMLE_Step_1] saghar: seems nothing going on...
01/17/05 15:59:29 [USMLE_Step_1] usmle_guy: yes, epidemiology and biostats
01/17/05 15:59:30 [USMLE_Step_1] mmw: hi tampa sagar
01/17/05 15:59:35 [USMLE_Step_1] zoya: cross sectional -prev, case- control is retro, cohort is prospective.
01/17/05 15:59:41 [USMLE_Step_1] tampa: what has happened with the transcripts from previous chats
01/17/05 15:59:41 [USMLE_Step_1] zoya: hi tampa
01/17/05 15:59:48 [USMLE_Step_1] tampa: hi
01/17/05 15:59:49 [USMLE_Step_1] zoya: hi saghar
01/17/05 15:59:50 [USMLE_Step_1] saghar: I thought it started at 3 ES time
01/17/05 16:00:18 [USMLE_Step_1] usmle_guy: previous chats are lost because the rox has had some personal problems to deal with
01/17/05 16:00:37 [USMLE_Step_1] saghar: I don't know about the transcripts, after patho neoplasia it stopped..
01/17/05 16:00:58 [USMLE_Step_1] usmle_guy: we are trying to move the chats to night time. is 8 pm eastern ok with the people who just came in?
01/17/05 16:01:11 [USMLE_Step_1] tampa: oh no I am at work and cant stay long. So I am better off reading the transcripts
01/17/05 16:01:12 [USMLE_Step_1] zoya: i don't think there were any chats after that.
01/17/05 16:01:12 [USMLE_Step_1] saghar: and I checked here everyday, but there was no chats!!
01/17/05 16:01:35 [USMLE_Step_1] tampa: 8 will be great for me
01/17/05 16:01:43 [USMLE_Step_1] saghar: that's fine with me too.....
01/17/05 16:02:10 [USMLE_Step_1] usmle_guy: yes, rox is the coordinator, but she has had personal issue to deal with and hasn't been able to make it. so the chats have been unorganized over the past week or so
01/17/05 16:02:28 [USMLE_Step_1] tampa: so the only chats for path were until neoplasia?
01/17/05 16:02:50 [USMLE_Step_1] saghar: So are you guys going to have chat tonight?
01/17/05 16:02:57 [USMLE_Step_1] usmle_guy: from tomorrow onward, lets all try to get the word out that the time is moved to 8 pm eastern time so that we can get the big group going again
01/17/05 16:02:58 [USMLE_Step_1] saghar: yes
01/17/05 16:03:08 [USMLE_Step_1] tampa: ok
01/17/05 16:03:15 [USMLE_Step_1] saghar: fine
01/17/05 16:03:21 [USMLE_Step_1] usmle_guy: no some other chats, but nobody posted the transcripts
01/17/05 16:03:28 [USMLE_Step_1] tampa: going with which schedule?
01/17/05 16:03:31 [USMLE_Step_1] saghar: what is the subject?
01/17/05 16:03:40 [USMLE_Step_1] saghar: epidemio and biostat?
01/17/05 16:03:49 [USMLE_Step_1] zoya: mmw have you heard anything from rox?
01/17/05 16:03:50 [USMLE_Step_1] usmle_guy: not tonight. we are already chatting today (now), so we start again tomorrow at 8 pm easten
01/17/05 16:04:08 [USMLE_Step_1] saghar: ok, thanks.
01/17/05 16:04:15 [USMLE_Step_1] mmw: no i am still waiting for rox
01/17/05 16:04:30 [USMLE_Step_1] zoya: oh
01/17/05 16:04:48 [USMLE_Step_1] saghar: I saw here once in prep4usmle forum.
01/17/05 16:04:57 [USMLE_Step_1] saghar: I mean I saw rox there.
01/17/05 16:05:03 [USMLE_Step_1] zoya: ok
01/17/05 16:05:04 [USMLE_Step_1] usmle_guy: today (now) is epi and stats. tomorrow is Social Life in the US Substance Abuse Human Sexuality at 8 pm. everyday after that is the schedule that is posted, except at 8 pm eastern instead of 3
01/17/05 16:05:37 [USMLE_Step_1] zoya: ok
01/17/05 16:05:52 [USMLE_Step_1] saghar: ok, got ya..
01/17/05 16:06:16 [USMLE_Step_1] usmle_guy: should we continue with epi?
01/17/05 16:06:23 [USMLE_Step_1] tampa: so today will be ok
01/17/05 16:06:35 [USMLE_Step_1] saghar: I guess..
01/17/05 16:06:45 [USMLE_Step_1] clover: yes please repost last question.
01/17/05 16:07:43 [USMLE_Step_1] mmw: what is epidemiology?
01/17/05 16:07:51 [USMLE_Step_1] usmle_guy: when dealing with observational studies, which is for present, which is retrospective, which is for prospective? 3 separate answers.
01/17/05 16:08:21 [USMLE_Step_1] usmle_guy: epidemiology is a part of behavioral dealing with the overall statistics of a population
01/17/05 16:08:30 [USMLE_Step_1] zoya: case control retro , cohort prospective
01/17/05 16:09:14 [USMLE_Step_1] clover: case control sounds like "damage control", so retrospective. cross section is present. cohort is prospective
01/17/05 16:09:24 [USMLE_Step_1] mick: agree
01/17/05 16:09:39 [USMLE_Step_1] usmle_guy: yes, thats correct.
01/17/05 16:09:40 [USMLE_Step_1] saghar: present: cross sectional, retrospective: case control, prospective: cohort, rite?
01/17/05 16:09:47 [USMLE_Step_1] mmw: agree
01/17/05 16:10:16 [USMLE_Step_1] zoya: can you explain cross sectional........its not clear to me
01/17/05 16:11:34 [USMLE_Step_1] usmle_guy: cross sectional is the present or prevalence. if i asked "how many are tired right now?". this would be an example because it deals with those tired at the present moment
01/17/05 16:11:40 [USMLE_Step_1] tampa: i cant stay, but I will join in tomorrow at 8!!! Will this chat be posted as transcript
01/17/05 16:12:00 [USMLE_Step_1] usmle_guy: yes, i will post the transcript for today
01/17/05 16:12:08 [USMLE_Step_1] tampa: thanks
01/17/05 16:12:15 [USMLE_Step_1] zoya: thanks usmle
01/17/05 16:12:24 [USMLE_Step_1] usmle_guy: no problem. see you tomorrow tampa
01/17/05 16:12:46 tampa Logs Out
01/17/05 16:13:05 [USMLE_Step_1] usmle_guy: when you talk about "odd ratio", which study is this associated with?
01/17/05 16:13:22 [USMLE_Step_1] zoya: what is hawthorne effect?
01/17/05 16:13:35 [USMLE_Step_1] saghar: cohort
01/17/05 16:13:38 [USMLE_Step_1] clover: odds ratio is assoc with case control or retrospective
01/17/05 16:13:43 [USMLE_Step_1] mmw: case control
01/17/05 16:13:52 [USMLE_Step_1] zoya: case control
01/17/05 16:14:10 [USMLE_Step_1] saghar: sorry relative risk is used for cohort study
01/17/05 16:14:18 [USMLE_Step_1] mmw: retrospective and causuality
01/17/05 16:14:20 [USMLE_Step_1] saghar: it's case control
01/17/05 16:14:31 [USMLE_Step_1] usmle_guy: its the odds of getting a disease with exposure to suspected cause and associated with case control. very good
01/17/05 16:16:00 [USMLE_Step_1] clover: of the following, t test, anova, chi sq, which checks differences between the means of 2 groups?
01/17/05 16:16:18 [USMLE_Step_1] usmle_guy: t-test
01/17/05 16:16:39 [USMLE_Step_1] mmw: t-test
01/17/05 16:16:44 [USMLE_Step_1] saghar: t-test
01/17/05 16:16:48 [USMLE_Step_1] usmle_guy: mneumonic is "mr. T is mean"
01/17/05 16:16:52 [USMLE_Step_1] mmw: mr T is mean
01/17/05 16:16:59 [USMLE_Step_1] mmw: yes
01/17/05 16:17:09 [USMLE_Step_1] clover: yep
01/17/05 16:17:18 [USMLE_Step_1] clover: which one to copare percentages
01/17/05 16:17:24 [USMLE_Step_1] mmw: chi
01/17/05 16:17:32 [USMLE_Step_1] saghar: agree
01/17/05 16:17:34 [USMLE_Step_1] usmle_guy: chi squared
01/17/05 16:17:49 [USMLE_Step_1] clover: yep
01/17/05 16:18:33 [USMLE_Step_1] clover: what kind of bias when knowledge of presence of disorder alters recall by subjects?
01/17/05 16:18:48 [USMLE_Step_1] usmle_guy: recall bias??
01/17/05 16:18:52 [USMLE_Step_1] mmw: recall bias
01/17/05 16:19:01 [USMLE_Step_1] saghar: recall?
01/17/05 16:19:14 [USMLE_Step_1] clover: yep. sorry, i put "recall" in question by mistake
01/17/05 16:19:49 [USMLE_Step_1] mmw: information gathered an inappropriate time what bias?
01/17/05 16:20:06 [USMLE_Step_1] usmle_guy: late-look bias
01/17/05 16:20:11 [USMLE_Step_1] clover: late look
01/17/05 16:20:19 [USMLE_Step_1] mmw: yes
01/17/05 16:20:37 [USMLE_Step_1] clover: what about when subjects are not representative?
01/17/05 16:20:52 [USMLE_Step_1] mmw: substance choose groups bias?
01/17/05 16:20:58 [USMLE_Step_1] clover: darn, did it again :<
01/17/05 16:20:59 [USMLE_Step_1] zoya: selectionbias
01/17/05 16:21:41 [USMLE_Step_1] clover: nevermind, i didnt hit the send button lol
01/17/05 16:22:12 [USMLE_Step_1] clover: its sampling bias. selection is when the subjects choose the groups
01/17/05 16:23:41 [USMLE_Step_1] mmw: selection i think causse sampling is subs r not representatiove therefore the results r not generalized
01/17/05 16:23:42 [USMLE_Step_1] zoya: isn't selection and sampling bias the same?
01/17/05 16:23:58 [USMLE_Step_1] usmle_guy: what percentage of cases are within 2 standard deviations of the mean in a normal distribution?
01/17/05 16:24:04 [USMLE_Step_1] saghar: that's what I thought..
01/17/05 16:24:25 [USMLE_Step_1] saghar: 95.5%
01/17/05 16:24:43 [USMLE_Step_1] mmw: dunno
01/17/05 16:25:06 [USMLE_Step_1] zoya: 95.5%
01/17/05 16:25:14 [USMLE_Step_1] clover: i think they are the same, but not sure
01/17/05 16:25:27 [USMLE_Step_1] clover: agree, 95.5%
01/17/05 16:25:38 [USMLE_Step_1] usmle_guy: yes, 95.5%
01/17/05 16:25:42 [USMLE_Step_1] zoya: ok
01/17/05 16:26:12 [USMLE_Step_1] usmle_guy: what about 2 standard deviations ABOVE the mean?
01/17/05 16:26:45 [USMLE_Step_1] saghar: 47.5%?
01/17/05 16:26:52 [USMLE_Step_1] clover: i meant within 2 SD above mean
01/17/05 16:27:25 [USMLE_Step_1] clover: yes, 47.5 is correct. very good. most have trouble with that concept
01/17/05 16:27:44 [USMLE_Step_1] usmle_guy: thats right
01/17/05 16:27:51 [USMLE_Step_1] zoya: rt
01/17/05 16:27:56 [USMLE_Step_1] mmw: how do u calculate those i don't understand
01/17/05 16:28:19 [USMLE_Step_1] saghar: refer to the nl dostribution graph on page 20 of kaplan
01/17/05 16:28:28 [USMLE_Step_1] usmle_guy: mmw, do you have a pic of the normal curve with the percentages?
01/17/05 16:28:53 [USMLE_Step_1] mmw: i will go and check now
01/17/05 16:28:55 [USMLE_Step_1] saghar: 34% one SD above plus 13.5 % for the second SD above the mean equals to 47.5%
01/17/05 16:29:42 [USMLE_Step_1] zoya: above the mean on positive side
01/17/05 16:29:53 [USMLE_Step_1] mmw: oh ok i got it
01/17/05 16:30:23 [USMLE_Step_1] usmle_guy: check out this thread with great question and explanation. great visuals too http://www.valuemd.com/ftopic10278.html
01/17/05 16:30:47 [USMLE_Step_1] mmw: thanks million i have to read it again cause i did not study recently
01/17/05 16:31:31 [USMLE_Step_1] mmw: ok gotya
01/17/05 16:31:35 [USMLE_Step_1] clover: thats a very high yield concept that we should all learn cold because very likely to see on exam
01/17/05 16:32:24 [USMLE_Step_1] saghar: if we increase the upper limit normal of a test reference interval what happens to sens and spec?
01/17/05 16:34:10 [USMLE_Step_1] saghar: like we increase the ref interval of a test from 4 to 10?
01/17/05 16:34:15 [USMLE_Step_1] usmle_guy: if increase the upper limit of normal, i think it would decrease sens and increase specificiy
01/17/05 16:34:27 [USMLE_Step_1] zoya: less sensitivity but morespecificity
01/17/05 16:34:35 [USMLE_Step_1] saghar: correct
01/17/05 16:35:31 [USMLE_Step_1] saghar: now what happens to PPV and NPV?
01/17/05 16:36:20 [USMLE_Step_1] mmw: ppv inc and npv dec?
01/17/05 16:36:29 [USMLE_Step_1] usmle_guy: NPV would dec and PPV would inc
01/17/05 16:37:01 [USMLE_Step_1] saghar: right, ppv increases and NPP dec.
01/17/05 16:37:14 [USMLE_Step_1] usmle_guy: i think that the common example is the recent (few years ago) lowering of fasting glucose level for diagnosing diabetes mellitus from >140 to >126. what effect on sens and spec, NPV, PPV?
01/17/05 16:38:08 [USMLE_Step_1] saghar: sen and NPP increases, spec and PPV decreses
01/17/05 16:38:21 [USMLE_Step_1] zoya: sens inc, spec dec
01/17/05 16:38:44 [USMLE_Step_1] mmw: agree to saghar
01/17/05 16:38:47 [USMLE_Step_1] clover: agree
01/17/05 16:38:50 [USMLE_Step_1] zoya: ppv inc
01/17/05 16:39:02 [USMLE_Step_1] zoya: opps sorry
01/17/05 16:39:03 [USMLE_Step_1] usmle_guy: this is the opposite of saghars example because you would be DECREASING the upper limit in this case, so an increase in sens and NPV, and a dec in spec and PPV. very good
01/17/05 16:39:20 [USMLE_Step_1] zoya: ppv dec
01/17/05 16:39:32 [USMLE_Step_1] usmle_guy: thats right zoya
01/17/05 16:39:49 maceiro33 Logs in
01/17/05 16:40:32 [USMLE_Step_1] clover: vaccination is an example of what type of disease prevention? primary, secondary or tertiary?
01/17/05 16:40:46 [USMLE_Step_1] usmle_guy: primary
01/17/05 16:40:57 [USMLE_Step_1] saghar: primary
01/17/05 16:41:56 [USMLE_Step_1] clover: yes. what about exogenous insulin for diabetes? what about a pap smear?
01/17/05 16:42:16 [USMLE_Step_1] usmle_guy: pap is secondary, insulin is tertiary
01/17/05 16:42:27 maceiro33: Hello some have been taken the CS , I need some experience
01/17/05 16:42:29 [USMLE_Step_1] saghar: agree with usmle_guy
01/17/05 16:43:09 [USMLE_Step_1] clover: yep, thats right
01/17/05 16:43:17 mick Leaves Subroom
01/17/05 16:43:44 mick: maceriro, if your looking for step 1 chat, its in the step 1 room
01/17/05 16:43:51 mick Joins Subroom USMLE_Step_1
01/17/05 16:44:52 [USMLE_Step_1] usmle_guy: which hypothesis, null or alternative, says that the findings are the result of chance or random factors?
01/17/05 16:45:08 [USMLE_Step_1] clover: null
01/17/05 16:45:15 [USMLE_Step_1] zoya: null
01/17/05 16:45:17 [USMLE_Step_1] mmw: null
01/17/05 16:45:18 [USMLE_Step_1] saghar: null
01/17/05 16:45:27 [USMLE_Step_1] usmle_guy: correct all
01/17/05 16:45:47 [USMLE_Step_1] mmw: disease and risk have no relation right? in null
01/17/05 16:45:55 [USMLE_Step_1] saghar: rite
01/17/05 16:46:22 maceiro33: No, I said Clinical Skill The previoUS CSA, iN Atlanta , or Chicago.
01/17/05 16:46:25 [USMLE_Step_1] usmle_guy: thats right. it means its by chance
01/17/05 16:46:35 [USMLE_Step_1] mmw: if the disease and risk factor have little relation what ?
01/17/05 16:46:45 [USMLE_Step_1] saghar: alternative
01/17/05 16:46:59 pharmacology Logs in
01/17/05 16:47:10 [USMLE_Step_1] saghar: or H1
01/17/05 16:47:26 maceiro33 Joins Subroom Clinical_Skills
01/17/05 16:47:32 pharmacology Joins Subroom USMLE_Step_1
01/17/05 16:47:36 pharmacology Leaves Subroom
01/17/05 16:47:53 pharmacology: I think you have to click on USMLE_Step 1
01/17/05 16:48:00 [Clinical_Skills] maceiro33: Hello somo information regarding Clinical Skill
01/17/05 16:48:00 [USMLE_Step_1] usmle_guy: you mean if it has little statistical significance?
01/17/05 16:48:09 pharmacology: You are in the main room
01/17/05 16:48:25 [USMLE_Step_1] saghar: assume that a test has a highest sensetivity, what happens to prevalence?
01/17/05 16:48:25 pharmacology Leaves Subroom
01/17/05 16:48:30 pharmacology Joins Subroom USMLE_Step_1
01/17/05 16:48:40 pharmacology Leaves Subroom
01/17/05 16:49:01 [USMLE_Step_1] usmle_guy: so lots of people have the disease, so i guess that prevalence would increase??
01/17/05 16:49:22 pharmacology Logs Out
01/17/05 16:49:27 [USMLE_Step_1] saghar: that right,prevalence inc, good job !
01/17/05 16:50:13 [USMLE_Step_1] clover: when you fail to reject the null hypothesis when it is really true, what type of error is this? 1 or 2?
01/17/05 16:50:25 [USMLE_Step_1] usmle_guy: 2
01/17/05 16:50:47 [USMLE_Step_1] saghar: type II
01/17/05 16:50:56 [USMLE_Step_1] mick: type II
01/17/05 16:51:11 [USMLE_Step_1] clover: yep, type 2
01/17/05 16:51:13 [USMLE_Step_1] mmw: is it 1?
01/17/05 16:51:36 [USMLE_Step_1] zoya: sorry,i was gone for awhile............i have to go now bye everyone
01/17/05 16:51:50 [USMLE_Step_1] saghar: bye, see u later
01/17/05 16:51:51 [USMLE_Step_1] zoya: see you all tomoorow
01/17/05 16:51:55 [USMLE_Step_1] clover: bye zoya. see you tomorrow at 8
01/17/05 16:51:58 [USMLE_Step_1] mmw: oh yes i did not see fail to reject
01/17/05 16:52:05 [USMLE_Step_1] usmle_guy: bye zoya
01/17/05 16:52:18 [USMLE_Step_1] mmw: bye zoya see u tomorrrow
01/17/05 16:52:38 [USMLE_Step_1] zoya: bye
01/17/05 16:52:40 zoya Logs Out
01/17/05 16:52:58 [USMLE_Step_1] usmle_guy: i think we covered alot today. unless anyone has anything specific?? so next chat is tomorrow at 8 pm eastern instead of 3....spread the word
01/17/05 16:53:34 [USMLE_Step_1] clover: ok, good to see the chat going strong again. see everyone tomorrow night
01/17/05 16:53:38 [USMLE_Step_1] mmw: ok usmle
01/17/05 16:53:56 [USMLE_Step_1] saghar: alright, thanks for the qs, see you all tomorrow. bye......
01/17/05 16:53:57 [USMLE_Step_1] mmw: r u going to post todays
01/17/05 16:54:19 [USMLE_Step_1] usmle_guy: yes, i'll post the transcript. study hard and see everyone tomorrow
01/17/05 16:54:32 [USMLE_Step_1] mmw: see u all tomorrow guys take care
01/17/05 16:54:38 [USMLE_Step_1] mmw: thanks
01/17/05 16:54:50 [USMLE_Step_1] clover: tomorrows topics from ** are Tuesday Jan 18 Social Life in the US Substance Abuse Human Sexuality
01/17/05 16:54:55 [USMLE_Step_1] clover: bye
01/17/05 16:55:05 [USMLE_Step_1] saghar: bye
01/17/05 16:55:09 saghar Logs Out