Saturday, March 31, 2012

Two other kinds of personalities

Coming from the previous post on borderline and paranoid personality, maybe today we could talk about two other personality disorders - these two are very common in daily parlance, though those speaking of it quite often have little idea what's under the words...

Histrionic personality disorder

People with histrionic personality tend to be self-centered and attention-seeking. They have a shallow, labile affect which they display in a dramatic manner. They are often flirtatious and inappropriately seductive – however, their sexual feelings, like their emotions, are often shallow and they often fail to achieve orgasm despite elaborate displays of passion.

They are overconcerned with physical attractiveness. They often repeat themselves, often to achieve self-deception (as in believing in one's own lies)

Narcissistic personality disorder

People with this disorder have a grandiose sense of self-importance and are boastful and pretentious. They are preoccupied with fantasies of unlimited success, power, beauty and intellectual brilliance. They think that they are special and entitled to special services and favors.

The phenotypic feature is thus the tendency to exploit others, as well as being envious of other's success.

Placebo: Ahh it is really difficult to write an article a day.

Thursday, March 29, 2012

Personality problems

People with personality problems are commonly seen in clinics[1]. It is in fact a cluster of problems which is even more troublesome than most other psychiatric problems. Some of these problems affects the person (patient) more than others, others affect the people surrounding the person having the problem.

"Psychosis, you can treat, but personality disorders, not really." - said my friend who is now a psychiatrist.

This in fact reflects both the resistance to treatment, as well as the general resentment that such disorder actually occurs in our population, and in our clinics.

Some personality disorders are very traumatic to others (not that these are not traumatic to oneself):

Paranoid personality disorder

People with this kind of personality are suspicious and sensitive. One can see a marked sense of self-importance but you can always feel a hint of shame, and humiliation, in their eyes, even after minor setbacks.

They are keen observers, as observant as the best scientists, they search not for scientific hypotheses, but attempts by others to deceive them.

They are very sensitive to rebuff, they are prickly and argumentative and they often read between the lines to see non-existent threatening meaning in obviously innocent remarks. They never forgive others for real or imagined threats, and they often seek revenge in this modern society by hiring lawyers and proceeding to litigations (often unnecessarily).

Borderline personality disorder

You see extreme efforts by them to avoid abandonment - they manipulate others by acts such as recurrent suicidal behavior to relieve themselves of their chronic feeling of emptiness. They are impulsive, they can't control their anger.

People often quote these borderline people to have intense, but brief, and unstable relationships, and this is true, and in addition, approaching the end of their relationship, you see paranoia in their behavioral pattern, and they become suspicious when they are stressed.

What's the personality problem described here?

[1] Not that I don't have one. I am a dependent person. Dependent on my girlfriend.

Test concepts

To be honest, these days, many patients come to the hospital for tests rather than for consultations, and for (self-prescribed) treatment rather than diagnosis.It seems to us that when we offer a test (instead of history taking and physical examination), the patients are more satisfied and many of them still hold the belief that the tests are invariably correct.

And this is not a small mistake to make.

When we look at tests, we look at the test result (e.g. a blood test), compared to the actual result (whether the patient actually have that particular condition).

positivetrue positivefalse positiveTP/(TP+FP) = PPV
negativefalse negativetrue negativeTN/(TN+FN) = NPV

TP/(TP+FN)=Sn  TN/(FP+TN)=Sp

PPV = Positive predictive value
NPV = Negative predictive value
Sn = Sensitivity
Sp = Specificity

Sensitivity and Specificity are inherent to the test itself - it depends on the test itself, and the cutoff value chosen only. When different values are chosen as the cutoff for a test, the sensitivity varies with specificity, and we can plot a graph that is known as the "Receiver operating characteristic curve" (Wiki on ROC curves)

Sensitivity measures how good the test is at detecting the condition when the condition is present. Specificity measures how good the test is at ruling out the condition when the condition is absent.

The detail for the ROC curve isn't that important - but it is important to know that if you pick a value that makes the test more sensitive, the specificity will go down, and if you pick a value that makes the test more specific, the sensitivity will go down. The clinical implication that, if you want doctors to have very few misses in diagnosing a condition, doctors are going to do a lot more tests on everybody, and most of these tests will turn out negative.

Take the sample ROC curve above as an example, if you want the sensitivity to go as much as 90% (i.e. 90% of patients who have the disease the test will be tested positive) then the specificity will fall to 40% (i.e. only 40% of those who do not have the disease will test negative - or, put it the other way round, 60% of those who do not have the disease will test positive). These patients who are so unfortunate to have a false-positive result will be subjected to confirmatory tests, which are often more invasive and incur morbidity and mortality - for example, a 0.25-0.5% risk of death following a diagnostic coronary angiogram.

And then we come to the positive and negative predictive value. We talked about the sensitivity and specificity being inherent to the test and being related to the cutoff value chosen - the positive predictive value and negative predictive value depend very much on the prevalence of the condition (i.e. the number of people having the condition in the population)

For example, let's say we have a population of 1000 (e.g. in a secondary school) that we are going to test for drug use. There are, let's say, 20 students abusing the drug. And our tests are 95% sensitive while 95% specific.

present     absent
positive1949 PPV = 27.9%
negative1931NPV = 99.9%

We can see that the tests is inappropriate for this application - We are going to have 49 false positive among these 1000 students. Imagine the psychological trauma and the effect of labelling in these students while confirmatory tests are being done.

Imagine the same test being done in another school where drug problem is very severe - 200 students are abusing the drug:

present     absent
positive19040 PPV = 82.6%
negative10860NPV = 98.8%

The result looks much nicer compared with the previous one - with the same test, same cutoff (and thus same sensitivity and specificity). We can see that this test is much more suited to the application in this particular school.

What does all these mean to the readers, then?

Looking at it, human decision making is also a test (even if no laboratory resources are used), It means that, the higher the quality (i.e. the lower the miss-rate) you require from the doctor, the more tests will be done on you, and many of them will eventually going to be negative, and worse still, some of them are going to be false positives.

Wednesday, March 28, 2012

Liberal education - Looking back


There has been quite a body of discussion on the establishment of liberal studies. Various published articles, most prominently on Hong Kong Teachers' Centre Journal, have already listed out the difficulties of establishing such a subject in Hong Kong, citing reasons such as (1) Lack of a clear scope for liberal studies, (2) Necessity of an adequate prerequisite base of knowledge before the appreciation of the intrinsic value of liberal studies,(3) Lack of established teaching protocols, (4) Lack of applicable teaching materials, and the detrimental effect of establishing a standard one, (5) Lack of staff development on the subject, (6) Lack of substantial guidelines, etc. [1]

Whereas some of these concerns have been addressed by the issuance of formal guidelines on the development of liberal studies, vacuum still exists (despite how the nature abhors it) even though the academic exploration of it started some 5 years ago.

Liberal studies and general education

Originally, the term to the academia was that of general education, and it is perhaps a response to the increasing specialization of undergraduate courses that spurred in the 1970s (especially in the US of A). There, it was noted that although these new graduates are extremely knowledgeable in their own field, they are often ill-informed in most other fields.

To quote, the question at the end of the 1970s was that of whether the universities and colleges could continue their strengths in specialization, and at the same time offer something more, like, a liberal, general education[2].


While the difficulty of establishing a general education system at a university level is to get the departments to provide manpower to the courses and to design the courses such that it is understandable to the uninitiated, the difficulty in establishing a general education (or liberal studies) system at the secondary level is the lack of scholars who are able to teach.

While the level of knowledge that would eventually be tested would not be excessively difficult, it is to the interest of students, that each element of general education (as in science, social sciences and humanities) be taught by somebody who is well informed in each of those subjects.

It is perhaps to the advantage of students that the curriculum development of liberal studies in Hong Kong has always been ignoring the scientific part of it – such that,at the very least, a student won’t be taught on, for example, the scientific method (which, unsurprisingly, is an integral part of liberal studies curriculum elsewhere) by a teacher who has not even been instructed formally for it in a tertiary setting.

The good ol’ days of liberal studies

In the olden days, students are formally required to take almost all subjects while in junior forms, including literature, history, geography, integrated science and so on. This, perhaps, is actually the ideal picture of general education, and liberal studies at work. Each subject was taught by a relatively specialized teacher, relatively knowledgeable in their own field, and was ready to answer the question in an unambiguous manner.

It is perhaps to the best interest of students that we actually divide it back into pieces, and allow each piece of knowledge to be delivered by those in the know.

[1] see H K Kwok. The implementation of Liberal Studies in Hong Kong and its strategies, published in 2007, in Hong Kong Teachers' Centre Journal (pp1-6), for further discussions.
[2] see J Scott Lee. Liberal studies and general education in the undergraduate curricula in the 21th century: their role, development and the challenges.(Presentation available from google search)

This article is an edited version of my original post in an education forum.

Completing the family, for researchers

Completing the family (i.e. having children) is a rather controversial topic especially for female researchers. It is not only the time off that comes from the planning, child-bearing, delivery and child-rearing, but also the change in family status which mattered.
Getting a child is perhaps going to take a big toll on the research and teaching that one is currently doing but this is important for at least two reasons:-

1. The birth of the child to one, or occasionally a pair of academics would mean that they will be raised in a better environment than an average person. The environment will likely foster a child of good, if not great intellectual capacity.
2. A completed family is a continuing family. Living alone at an old age is lethargic at best - and believe it or not, academics are destined to be long-living. A family, especially one with children, will continue to supply the elder member of the family with vitality that is fading out with age.

This article is an edited version of my original post in an education forum.

Nursing - is it really THAT attractive?

A whole lot of people are asking about the working condition/hours/undergraduate curriculum (and so on and so forth) of nursing in the forums. I have always wondered - why is there so much interest in the society in becoming a nurse? Granted, salaries for nurses are among the highest if you look at the admission grades, but then is it really such an attractive package? If so, are those who aimed at pursuing the nursing profession suitable to do it?

I personally think that being a nurse, or for that matter a doctor, is a job that is in fact not really well paid for the necessary work. The price-performance ratio might as well be better for nurses but basically there is too much risk to bear for that particular salary. If I were for the salary, the medical industry would be down on the bottom of the list in applying for jobs.

For that mere 20k/month salary, one has to deal with infectious blood, urine, faeces, cerebrospinal fluid or even semen -- and then, as much as I hate to say it, unreasonable patients represent a significant portion of daily work in a hospital environment, be it in public or in private sector -- if you are lucky, you get scolded, if you are unlucky, you could be (unreasonably) complained, harassed or even beaten. Contracting HIV during procedures such as suction and blood taking is not something unheard of in the industry.

And here goes the shift work. Most nurses need to work shifts - be it in the operating theatre or wards - some may be exempted from shift work because of work location (outpatient department, day ward, etc.) but these places are often staffed by nurses with morbidities such as psychiatric illness or autoimmune diseases. Shift work imposes a lot of stress on the physical, psychological and social well-being of an individual.

If I were them, I probably wouldn't choose this subject as a career - there are a lot of career choices in which, if one is willing to work in such hazardous environment, in such irregular hours I think they are going to success and excel wherever they work.

Tuesday, March 27, 2012

New immigrants from China

Talked with a few other fellow doctors in the recent week and we kind of summarized what we saw in terms of the epidemiology of diseases in these new immigrants. These represent of course, anecdotal evidence and are not backed up by statistical tests[1].

Demographics of these new immigrants

There are basically four groups of immigrants. The first of them would be the ladies aged around 30-40 by now, which corresponds to the time when the vast interest in searching for wife in mainland began. The second, would be the kids that were first raised in mainland and brought to Hong Kong in the past 10 years. The third, would be working people holding the one-way permit, and the last group is the rather old people that were brought to Hong Kong to be cared after. I will focus on the first two groups.

First group of new immigrants: Ladies around 30-40

The major illness that comes in this group is anxiety-depression and female genital tract diseases. It is of no surprises that the prevalence of VDRL positivity and HPV positivity is much higher in this group of people and we are seeing a lot of really young patients with cervical cancer.

For the psychiatric part though, are really the fault of the Hong Kong people - their husband by the time now is already some 60, 70, or 80, and more often than not their husband are of the lower social class, and their health is poorly managed. You see them crippled by illness such as cerebrovascular accident, chronic obstructive airway diseases et cetera and it is really an ever-lasting difficulty for these ladies to care for their husband.

As to the female genital tract aspect however, it is more of a selection bias which I do not attempt to discuss here.

Second group of new immigrants: Kids raised in China

The problem with these kids is mostly psychiatric, and sometimes learning. It is not a surprising thing that students in Hong Kong in the past (during the British rule) has been shown to be superior in terms of their mental capability compared with peers in the western countries.

And our education system, unsurprisingly, is extremely high stress -- our top students (whom, are selected from a population of a mere 7 million) are able to get into the top universities, more often than our mainland counterparts (whom are selected from a country of 1.2 billion). After all, when we say that our medical examination is having so high a standard that it fails half the candidate, do we remember that our HKCEE fails (as in making the student not acceptable to matriculation courses) up to 80% of candidates in the past[2]?

The problem with these kids (or young gentlemen/ladies) is that they find it very difficult to position themselves in Hong Kong, where even local professionals have difficulty in living a reasonably cozy life.They often end up in two routes - one is early psychosis, and another substance abuse. They often do not have enough money and as a result, they will buy what they can afford - ketamine. The street price of ketamine, according to the police who presented in the HA toxicology conference this year, is around HKD$120 per bag, and each bag, could be used by first-time abuser for 5-6 times, thus it is just around HKD$20 per trip. Comparing the experience of two ketamine trips to a so-so lunch in [insert fast food chain here] which would cost you about the same amount of HKD, and without the knowledge of the consequences, I am sure we can understand why these kids would choose ketamine over the lunch.

I guess we can talk about the other two groups in the next few days...

[1] We do, however, have a firm belief that if statistical tests are being done then it has a real high change of being significant although an analysis like this has almost zero chance of passing through the ethics committee...
[2] Of course we understand that the medical doctors are a selected group compared with the relatively unselected group of HKCEE sitters...but anyways, there are three kinds of lies - lies, damn lies, and statistics.

Monday, March 26, 2012

Are we really helping the society to get more talents?

Are we really helping the society to get more talents?
A rather long rant

The education system in Hong Kong has undergone dramatic change which accumulated into the establishment of a new examination system, HKDSE, starting in 2012.The aim of an education system is of course to foster the development of talented person for the society, but then is our system really doing this? Are we really changing for the better?

A social worker has pointed out, during an episode of Hong Kong Connection (鏗鏘集), on how the bourgeois had cast their vote of no confidence by walking away from the government-sponsored education system in Hong Kong to the international schools, which, according to some, foster learning by providing an environment that is more dynamic and less examination-oriented. This behavior is of course not without its consequences, with eventually more local Chinese occupying positions in international schools and increasingly fierce competition for the places in it. Some foreigners who worked in Hong Kong could no longer find a place for their children to study in because they simply do not learn enough Chinese to allow education in the local system, nor could they secure a place in these international schools because of the fierce competition[1].

The problem with the change is that the education system has been modified in such a way that it promotes grade inflation, disproportionate amount of resources spent on particular groups of students, and increasingly, education for those who don't really want it.

Grade inflation

We are admitting an increasing number of students into our higher education system every year - be it in the statutory universities, in the statutory institutions, approved post-secondary colleges, VTC or other institutes which are accredited by the Hong Kong Council for Accreditation of Academic and Vocational Qualifications (What a long name!).

In the past, most of these students would have failed (and for the matter, some of them still failed) in the certificate examination (or eventually, for some, in the advanced level examination) and they do not have a chance of receiving tertiary education - their situation was perhaps not as bad as one would be in, these days, without a tertiary qualification, because a degree was not perceived as a must back then.

The grade inflation comes from three sides - the first side is that a reasonable curriculum has to be defined for a degree or other qualifications that is to be conferred; the second side is the institutional need of passing a reasonable number of students per year; the third side is the admission quality. One has to understand, that, despite the increase in overall intelligence in the general population, the number of those who could actually demonstrate good understanding in an undergraduate-level curriculum is definitely limited. I for one could not, really, achieve good understanding of a mathematics degree, for example, despite that I have finished my medical degree - it's not only a matter of intelligence, but also a matter of specific talent.

And then, now that an instructor, or a lecturer is now in charge of teaching students who failed their A-level physics AND applied mathematics, in an associate degree or perhaps a higher diploma program in the discipline of Engineering, what do you do? Do you change the curriculum? (not possible) Fail most of them? (not acceptable to the institution) or do you just inflate the grades? (the easy way out).

I am not saying that this is a specific problem of the education system in Hong Kong - in fact,  this is happening in a global scale even in the best universities - but the fact that this problem is global doesn't mean that it could immediately be passed as normal -- we still need to do something about it.

Disproportionate amount of resources spent in groups of students

In the past, there were the special education program, and there were the gifted education program (basically organized by the Faculty of Education, CUHK - The Program for the Gifted and Talented). Nowadays, we do not see as much emphasis in these and in fact, we are seeing a lot of money (and man-hour) being spent on remedial programs.

Remedial programs are definitely not news - we have remedial program, especially for language education since really long ago and it is everywhere - even in century-old establishments. The concept of remedial education is also not wrong - in a way, it is there to help those who could not learn effectively in the original classroom environment and provides a place in which the upper bar of student performance is lower, and the teacher-student ratio higher - this allows a teacher to teach a group of students in which the variance of ability is lower, and unsurprisingly this will lead to better received teaching.

The problem with remedial programs nowadays is that it is never-ending, and that it does not allow for additional time (as in academic year, not in lesson-hour) for the students to learn. A more terrible version of it has recently been developed by some band-2 schools which targeted a group of students who have trouble, but also 'hope' for a pass in the public examination - there, the students are divided into three groups:

(1) Those who are likely to fail despite remedial measures
(2) Those who are likely to benefit from remedial measures
(3) Those who are likely to pass the examination irrespective of remedial measures

And to make it further extremist, they are precluding the students categorized in (1) from coming to the remedial classes. Not that this is not utilitarian-correct,  but imagine the psychological health of the students so-categorized!

Then we look at the higher education. Higher education is an extremely expensive business, and I think most of us understood this.

The notion that the newer generation ought to have some sort of higher education has  been engraved onto the mind of parents in Hong Kong. The issue with these, though, is that they have to understand that the university is supposed to be a place for the advancement of science and arts, and we are looking for potential researchers in university education -- University education is NOT vocational training, and NOT a continuation of secondary school studies. To further the advancement of science and arts, however, is definitely not something that everybody is suited to do.

Education for those who don't really want it (and it is really parents' problem)

Most of us would understand that motivated students are some of the best students one would have in any education establishment. And the one of the worst problem we are having in the 21st century is that most of our students aren't motivated enough.

The best students often study because the subject matter itself is interesting to them - there is little else that is contributing as to why the student study. This is what people refer to as intrinsic motivation.

The lack of intrinsic motivation could be due to the vast array of distractions available these days, like computer games, TV programs, magazines, etc, but it could also be the diminished exposure of certain subjects to students which makes it increasingly difficult for students to actually find their true love -- a subject that is of their interest. For one, if you have never introduced to a subject like, bioinformatics for example, how does one get to like it?

This is not yet the worst enemy. Now that we have a wave of parents who are completely clueless as to how to rear a child, for example - we have parents who feed their newborn 3 times per day, essentially starving them to a near-fatal state, it is not surprising that they will foster learning in their child the wrong way. Some of them would provide a lot of extrinsic motivators without understanding the effect of it and the correct way of using it. And then when they find that the rewards don't work any more because of tachyphylaxis, they blame it on the teacher (you can't expect them to have learnt education psychology, could you?)

By now we can see that the causes of the motivation problem can be summarized below:

(1) They don't even get to develop the interest in a subject because they are not even exposed to it adequately.
(2) There are too much distraction these days
(3) Parents are often giving rewards the wrong way


With all these problems it is difficult to see how the new generation could actually learn - perhaps the education system would act as a sieve that allows only the best students to pass through, but this is currently at the cost of educating so many people who are really unwilling to learn (in "band 2 and 3 secondary schools" and in non-university tertiary education).

Could we have done better?

[1] Not that the government is obliged to provide them with it though, but this will surely hamper professionals from coming over.
[2] Formerly, there was also an examination for primary school graduation, but this is perhaps too old for me to comment on. Comments from readers with experience in the former system is encouraged. I refer the change to the changes imposed on the academic year 1996-1997. 
[3] Well, if they tried to foster their children's learning, it is already better than a 'so-what attitude' that is quite common these days... 

Edited 27.3.2012 - Mostly English usage (Too many complaints from my girlfriend)