Thank you for your interest in our article.[1] In our opinion, your
comment, that
gross household income (GHI) changed 24% of the increased risk among
unskilled workers is not a real change, does not take into account that
the two analyses are dependent. (Table 3, the two first columns). If the
Hazard Ratio was 1.24 (the lower limit of th...
Thank you for your interest in our article.[1] In our opinion, your
comment, that
gross household income (GHI) changed 24% of the increased risk among
unskilled workers is not a real change, does not take into account that
the two analyses are dependent. (Table 3, the two first columns). If the
Hazard Ratio was 1.24 (the lower limit of the CI) instead of 1.55, this
would also influence the Hazard Ratio in the model adjusted for GHI. We
do, however, agree with you that the change is minor. But it has to be
kept in mind, that there is no straightforward way to calculate CI for the
mediated proportion. You might be right that an independent effect of GHI
could show up if we stratified by occupational groups. Due to power
problems this was, however, not possible. The effect of income from other
adults in the family is accounted for as good as possible. But we agree
with you that not only income but also the occupational social positions
of other family members may also play an important role.
References
1) Andersen I, Gamborg M, Osler M, Prescott E, Diderichsen F. Income
as mediator of the effect of occupation on the risk of myocardial
infarction: does the income measurement matter? J Epidemiol.Community
Health 2005;59:1080-5.
Estimating the economic impact of ill health and the cost- benefit,
and cost effectiveness, of interventions intended to reduce it, is an
important but difficult exercise. The thoughtful paper by Rayner and
Scarborough is to be welcomed as a serious attempt to quantify one aspect
of this calculation: the direct costs to the NHS of treatment arising from
the proportion of certain diseases attributabl...
Estimating the economic impact of ill health and the cost- benefit,
and cost effectiveness, of interventions intended to reduce it, is an
important but difficult exercise. The thoughtful paper by Rayner and
Scarborough is to be welcomed as a serious attempt to quantify one aspect
of this calculation: the direct costs to the NHS of treatment arising from
the proportion of certain diseases attributable to inappropriate diets.
Any such estimate relies on a number of uncertain assumptions.
Unfortunately, the speculative nature of these assumptions, and the
consequent uncertainties as to appropriate policy responses, are likely to
be ignored when their conclusions are cited by others. It may be helpful
therefore to point out some important caveats to their analysis.
In Table 3 the cost of dental caries is included in a more general
classification with "other diseases of the digestive system" leading to an
estimate that these account for 8% of NHS costs. The source cited
indicates that all problems due to teeth account for about 3.8% of costs
in 2002/3, by no means all of which will be due to caries.
The other diseases in this arbitrary group "Dental caries
and other disease of the digestive system" are likely to be hugely more
expensive to treat than dental caries, providing one of many example that
should challenge their assumption that the proportion of costs to the NHS
can be equated to the proportion of DALYs that are estimated to be food
related.
While agreeing with their overall conclusion "..without quantifying
the burden of food related ill health we cannot say whether it is a
problem worth worrying about or not", this represents only the first stage
in the debate. Even when this estimate is known (and clearly precision is
not required - a ball park figure is more than adequate)there remain
unresolved questions as to the cost effectiveness of different approaches
to prevention and more fundamentally, the costs to the NHS (and the wider
economy) of successful prevention.
Here dental caries provides an unhelpful example. Prevention is most
effectively achieved by regular brushing with fluoride tooth paste (at no
cost to the NHS) and is likely to give virtually life long protection
against caries and thus from costs to the NHS. In contrast prevention (or
more likely delay) of cardiovascular disease into old age is likley to
lead to additional NHS costs in general health care during the additional
years of life and similar, or greater costs at the end of life. In
addition, the increased costs of State pensions arising from greater
longevity is already causing serious concern to the Exchequer.
The notion that prevention of all those diseases to which poor diets
may contribute will inevitably reduce costs to the NHS and benefit the
general economy remains arguable. The outcome of that economists' wrangle
should not detract from the overwhelmimg ethical case for better
prevention of diseases, whether food related or not.
The Sugar Bureau is funded by the sugar industries of Great Britain
and Ireland.
I most certainly agree with the “reviewer’ comments” cited by the
authors in the text of their paper; “The paper is timely and can be
potentially useful for health policy makers” (p. 1032). However, “timely”
in this case is a bit of an oddity. In response to a recent critique of
progress that I had written (Betts, 2005) a rather noted philosopher, who
is kind enough to review scholarly work for me fro...
I most certainly agree with the “reviewer’ comments” cited by the
authors in the text of their paper; “The paper is timely and can be
potentially useful for health policy makers” (p. 1032). However, “timely”
in this case is a bit of an oddity. In response to a recent critique of
progress that I had written (Betts, 2005) a rather noted philosopher, who
is kind enough to review scholarly work for me from time to time, asked
me; “I would think that this language [of Progress] is pretty hollow now.
Do your colleagues really believe it?” The point is, that serious
thinkers have not “believed” in Progress since – well perhaps since
Nietzsche (1990) suggested that;” “Mankind surely does not represent an
evolution toward a better or stronger or higher level, as progress is now
understood. This ‘progress’ is merely a modern idea, which is to say, a
false idea.” (p. 4), over a century ago. Though, certainly since Ivan
Illich gave the term iatrogenesis a whole new meaning. And yet virtually
all of our social and political institutions, particularly those of health
and welfare, are founded, perhaps even premised on the idea of Progress.
One wonders then, why it has taken so long for many of us, who generally
consider ourselves to be health practitioners of one kind or another, to
catch on to this serious problem of Progress? Could it be that we have
subscribed so heavily to a techno-rational science model, again
particularly in the health and welfare industry, that all of our, so
highly advertised, critical faculties have become stuck in a paradigm of
delusion? Indeed, in a recent article by Roy (2005), a chemist by the
way, aptly titled in my view; Scientism and Technology As Religions he
claims that; “Science-and-technology is the most powerful force under
human control; hence, scientific fundamentalism is the most dangerous.”
(p. 836). Of course Roy isn’t the first to suggest that techno-
rationalism (or scientism) may well constitute a religion of sorts, in
fact, once again a century ago, Nietzsche claimed something similar, as
have many others. In fact, more recently, Schaler (2002) has proposed
that health itself had indeed become a religion, with “the medical
profession as a priestly caste.” (p. 67).
Those of us who do the work of healthcare (be it diagnosis, intervention, education, promotion and what not) must now begin some serious thinking, or at any rate begin to pay
attention to some of the serious (anti-modern if you will) thinking that
has characterized the 20th century. Perhaps we might begin with a
question of the profoundest sort that has already, and again recently,
been proposed by Joseph Heath (2004); “Is it possible to emulate many of
the attractive features of western societies, while avoiding the social
pathologies?” (p. 665-6). While I do agree with the authors’ claim that;
“Public health needs to be more passionate about health issues associated
with human progress and adopt a health promotion stance.” (p. 1033), we
must also be careful for at least two reasons. The first concerns what
both Fitzgerald (1994) and Fitzpatrick (2001) refer to as The Tyranny of
Health, while the second is perhaps best summed up by Ulrich Beck
regarding his theory of reflexive modernity (or second modernity); “Due to
the close link between institutions that depend on one another to exist,
it can be assumed that processes of change and transformation in
particular parts of the structure will trigger problems in other parts
(the side-effects of side-effects)…” (Beck & Lau, 2005, p. 533).
Indeed, side effects are the order of the day, and nothing happens without
them happening. The problem then, for those who claim to be engaged in
the fixing of problems, is which side effects are good and which are bad.
Or put differently, which are acceptable and which are not. Moreover,
these are socio-political and socio-cultural issues of value, and they are
anything but scientific. Finally, in the spirit of the authors’ well put
claim that; “public health has to become more assertive and politically
aware…” (p. 1033), with, perhaps, a continuing attention to Foucault, let
us begin a plea for the progress of serious thinking about health, rather
than maintaining the modern course of unhealthy Progress.
References
Beck, U. & Lau, C. (2005). Second modernity as a research agenda:
Theoretical and empirical explorations in the ‘meta-change’ of modern
society. British Journal of Sociology, 56(4), 525-557.
Betts, C. E. (2005). Progress, epistemology and human health and
welfare: What nurses need to know and why. Nursing Philosophy, 6, 174–188
Fitzgerald F. T. (1994). The tyranny of health. N Engl J Med, 331,
196-198.
Fitzpatrick M. (2001). The tyranny of health: Doctors and the
regulation of life style. Routledge: New York.
Heath, J. (2004). Liberalization, modernization, westernization.
Philosophy and Social Criticism, 30(5-6), 665-690.
Nietzsche F. (1990) The Anti-Christ (tr. R.J. Hollingdale). Penguin,
New York.
Roy, R. (2005). Scientism and technology as religions. Zygon, 40(4), 835-844.
Schaler, J. A. (2002). Moral Hygiene. Society, May/June, 63-69.
This is a response to the e-letter sent by Dr Wenbin Liang. We
appreciate the comments and found them highly valuable.
Point 1. "The subjects of the study are collected from several
geographical clusters, and peoples health in the same hospital could be
strongly related....A small flu spreading among staff may affect the
incidence of medically certified sickness absence in one local emp...
This is a response to the e-letter sent by Dr Wenbin Liang. We
appreciate the comments and found them highly valuable.
Point 1. "The subjects of the study are collected from several
geographical clusters, and peoples health in the same hospital could be
strongly related....A small flu spreading among staff may affect the
incidence of medically certified sickness absence in one local employment
rate strata greatly".
Response: There are some points to be considered here. First, all
workplaces in municipalities and to some extent in hospitals are
physically spread across the town; in our data there are over 3000
different working units. Second, below are listed the different diagnostic
categories in explaining the medically certified sickness absence
incidence (>9 days) in Finland:
Musculoskeletal disorders 32%
Mental health disorders 15%
Injuries 13%
Cardiovascular diseases 7%
Respiratory diseases 6%
Disorders in digestive system 5%
Neurological diseases 4%
Tumours 4%
Pregnancy 3%
Urinary and venereal diseases 2%
Infectious diseases 1%
Other diseases 8%
Our results on the association between high local unemployment rate
and long-term (>8 days) medically certified sickness absence in women
were similar to those obtained for all medically certified absences. Thus,
common cold or other infections are unlikely to explain the present
results. In contrast, infectious diseases may have a great contribution to
self-certified sickness absence (of 1 to 3 days' duration).
Point 2: "The cloud could be cleared if the original data showed no
great variation of "medically certified sickness absence incidence in
different hospitals/municipalities which are within the same local
unemployment rate strata".
Response: As suggested, we re-analysed our data and found that there
was variation in the incidence of medically certified sickness absence
between the workplaces (10 municipalities and 15 hospitals). However,
there was statistically significant (p<.001) variation within all local
unemployment rate stratum (high, decreasing and low). However, the
workplace accounted only for 1-2% of the variation in sickness absence
incidence.
The Journal of Epidemiology and Community Health has recently
published two papers by Knox[1,2] which conclude that “childhood cancers
are strongly determined by prenatal or early postnatal exposures to oil
based combustion gases especially from engine exhausts. 1,3-butadiene, a
known carcinogen, may be directly causal”. This is a strong conclusion
for a study whose novel analysis uses only the birth...
The Journal of Epidemiology and Community Health has recently
published two papers by Knox[1,2] which conclude that “childhood cancers
are strongly determined by prenatal or early postnatal exposures to oil
based combustion gases especially from engine exhausts. 1,3-butadiene, a
known carcinogen, may be directly causal”. This is a strong conclusion
for a study whose novel analysis uses only the birth and death addresses
of childhood cancer cases and which uses atmospheric emissions data from
2001 as a surrogate for exposure that may have occurred as early as 1937
in the first report, or as early as 1955 in the second report.
Furthermore, Knox notes that the basic method of the study, and all the
results, depend upon a premise of a “migration equilibrium” among the
general child population. Strong claims are also made about the studies
in two accompanying editorials in the journal.[3,4] One editorial
acknowledges the lack of a proper control group, but still claims that the
papers contain “striking evidence relating atmospheric contaminants, and
mostly emissions derived from engine exhausts, with increased risk for
children of dying from leukaemia and other cancers”.[3] A second
editorial describes the work as “unique in its capacity to combine in a
meaningful way a series of routinely collected data on births, deaths,
residences, sources of exposure, and specific exposures”.[4] However,
this letter will demonstrate that a migration equilibrium cannot be
assumed and that Knox’s estimate of relative risk largely reflects the
relative likelihood of families living in the inner and outer exposure
zones to move house. Consequently the studies provide no meaningful
results and the findings should be disregarded.
The two reports by Knox aim to identify specific causal agents for
childhood cancer using methodology that links the birth and death
addresses of fatal child cancers (pre 1980) to current emissions hotspots
for specific chemicals. Knox has developed a methodology based on the
proximity of migrant children to pollution sources at birth and death
which he notes was initially dictated by the absence of a suitable set of
non-cancer controls in the study from which the case material was
extracted. For a particular definition of exposure (for example, living
within 1.0 km of an emissions hotspot), Knox estimates the relative risk
among the subset of children whose birth and death addresses differ in
respect of exposure by calculating the ratio of outward migrations (birth
address exposed and death address unexposed) to inward migrations. This
letter focuses on this estimator of relative risk because it has some
plausibility and the approach has been likened to a case-crossover study
design.[4] However, Knox also states that the ratio of births to deaths
is an adequate estimator of relative risk for short distances around
emissions hotspots although this clearly gives results that are
inconsistent with the migration ratio unless all families move house.
Knox acknowledges that the validity of his approach depends upon the
premise of a short term migration equilibrium among the general child
population and the second report[2] claims that this has been validated
in the earlier report.[1] However, Knox presents no data to test the
validity of this critical premise in either report and he only presents a
calculation of the scale of demographic movement that would be necessary
to explain the migration ratios that he has observed. In the case of 1,3-butadiene, Knox calculates that there would have to have been a net
general migration rate among children sufficient to have depopulated all
the exposed zones over the study period. However, this argument is
patently wrong as it overlooks the fact that the numbers of children in
the exposed areas will also be replenished by children born in these
areas. Knox’s premise of migration equilibrium is not only untested, it is
also readily apparent that is not valid as it completely ignores the
contribution of births (and deaths to a much lesser extent in the case of
children) to the maintenance of a population equilibrium. For example,
consider the housing stock at the foot of the housing ladder that is
rented or purchased by many young couples before they start a family. Many
of these couples will move to larger properties in better residential
areas after they start their families. Other families with young children
are unlikely to move into the properties and replace the children that
have left. However, the area will not become depopulated of children as
couples without children will move into the properties and start their
families as the cycle repeats. In contrast, many children living in larger
properties in better residential areas will grow up there and move out as
adults, and their parents are likely to be replaced at some point by
families with young children.
Kogevinas and Pearce[4] correctly identify that the findings of
Knox’s studies will be invalid if there is not a short term migration
equilibrium among the general child population or if there is a specific
tendency for families to move away from environmental hotspots after the
diagnosis of cancer in the child. However, they incorrectly state that
Knox attempted to address these two assumptions by restricting his
analysis to short migrations of less than 1.0 km. Knox did not perform
such an analysis in either report and most of Knox’s analyses are
restricted to migrations that were more than 1.0 km in distance. However,
there is sufficient information in tables 1, 2 and 5 of Knox’s first
report[1] to perform the analysis suggested by Kogevinas and Pearce for 7
of the 8 exposures that had the highest migration ratios in the analysis
of migrations greater than 1.0 km. The short distance migration ratio for
benzo(a)pyrene (BAP) could not be calculated because Knox gives different
numbers of hotspots in tables 1 and 5 for BAP (the lower limit for BAP
hotspots given in table 2 of Knox’s first report is also higher than the
figure given in the National Atmospheric Emissions Inventory (NAEI)
emissions maps[5]). However, the other 7 migration ratios for short
migrations (less than 1.0 km) range from 1.43 (1,3-butadiene, 33 outward
and 23 inward migrations) to 0.67 (benzene, 10 outward and 15 inward
migrations) with a median of 1.02 (PM10, 44 outward and 43 inward
migrations). Hence, the migration ratios for migrations of less than 1.0
km provide no evidence of an association between exposure and childhood
cancer.
Table 5 of Knox’s first report[1] also provides information about
the proportions of children born in the inner (within 1.0 km of a hotspot)
and outer exposure regions that migrated (any distance). For all the
exposures in Knox’s table 5, the proportions of children that migrated
were much higher for the inner exposure regions than the outer regions.
The largest difference is seen for 1,3-butadiene (inner migration rate =
80.1%, outer migration rate = 59.3%) and the smallest for BAP (inner
migration rate = 74.1%, outer migration rate = 65.1%). These differences
are strongly related to the magnitude of Knox’s estimate of relative risk
for exposure (based on migrant children with discordant birth and death
addresses). Knox obtained the highest estimate of relative risk for 1,3-
butadiene (3.73) and the lowest estimate of relative risk for BAP (1.92).
Furthermore, if the inner and outer migration rates are used to calculate
the odds ratios for exposure when comparing migrant and non migrant
children, then these are similar in magnitude to Knox’s estimate of
relative risk for an exposure. For example, 1,3-butadiene has an odds
ratio for migration of 2.73 and BAP has an odds ratio for migration of
1.53. However, there is absolutely no reason to expect any relationship
between a child moving house and their exposure. Knox’s estimate of
relative risk is largely a measure of the relative likelihood of a family
to move house in the inner and outer exposure zones and almost certainly
reflects differences between the type of housing to be found within the
inner and outer exposure regions. This is readily apparent when one looks
at the NAEI emissions maps.[5] Most of the exposures with high
outward/inward migration ratios have exposure hotspots that are mainly
situated alongside busy roads and/or in inner city areas. The housing in
these areas is often the sort of housing that families with young children
will try to move away from i.e. small terraces and flats. Nitrogen oxides
(NOx), 1,3-butadiene, benzene and PM10 are examples of such emissions and
the emissions map for NOx
(http://www.naei.org.uk/images/mapping_2002/6_large.png) is typical of
this group of emissions. In contrast, the locations of hot spots for
emissions with a high inward/outward migration ratio are very different. A
good example is the emissions map for nickel
(http://www.naei.org.uk/images/mapping_2002/16_large.png) with many of
the hotspots on the edges of urban areas situated close to housing areas
that are attractive to families. This also explains the surprising fact
that Knox obtained similar results in analyses of the different tumour
classes. Even if some of these agents are the cause of childhood cancer,
it is biologically implausible that they will affect all tumour classes.
It has been demonstrated that the outward/inward migration ratios are
not measuring the carcinogenic effect of substances or the non-specific
emissions from certain types of site as claimed by Knox. However, it
would also be very surprising if the 2001 modelled NAEI emissions data are
a good surrogate for exposure that occurred between 21 and 64 years
earlier (21 to 46 years in the second report). Knox focuses on 1,3-
butadiene, but this is one of the compounds for which the 2001 NAEI
emissions data are least likely to be representative of exposures so many
years earlier. Stationary source emissions for 2002 have now replaced the
information for 2001 on the NAEI website, but the emissions spreadsheet
for 2002 shows that there were 200 tonnes of emissions from 1134
stationary sources. Over 80% of the emissions occurred at just two
locations (97% from 8 locations). Most of the 1134 sites (96%) are
motorway service stations and supermarket filling stations that would not
have existed when the majority of the children in these studies were born.
Of the total of 3.5 ktonnes of 1,3-butadiene estimated to have been
emitted in 2002, 2.6 ktonnes were due to road transport activity.
Motorways and major roads are clearly shown as hotspots on the NAEI
emissions map. However, none of the motorways existed when the first
children in the studies were born and many did not exist when the last
children died in 1980 (although proximity to a motorway is also one of the
individual exposures studied by Knox).
It should also be noted that Knox is incorrect in two respects when
he states that the workplace exposure standard for 1,3-butadiene is 1 part
per billion (ppb), a limit which he says is not designed to prevent
childhood cancers. In fact, workplace exposure is limited to a maximum of
10 parts per million and the 1 ppb standard that Knox refers to is the
current UK standard for 1,3-butadiene in urban air (a running annual
average). This is a standard that is meant to protect all of the
population, including children, and it has been recently reviewed by the
UK Expert Panel on Air Quality Standards (EPAQS) who concluded that
“concentrations of 1,3-butadiene in the ambient atmosphere of 1 ppb
constitute so small a risk to the population as to be undetectable by any
feasible study”.[6]
In conclusion, it is clearly evident that Knox’s underpinning
assumption is not met and hence that the study has no control group and
the results are not interpretable. However, even if Knox had included a
comparison group of children who did not develop cancer, it is debatable
whether the results would have had much value because of the lack of valid
exposure information. An analysis restricted to short migrations of less
than 1.0 km which is less dependent upon the migration equilibrium
assumption,[4] shows no evidence of an association between childhood
cancer and birth proximity to Knox’s pollution hotspots. The studies are
fatally flawed and there is no basis for Knox’s conclusions and the
assertions made in the editorials that “studies such as this clearly
indicate the potential importance of specific environmental exposures in
the causation of cancer in children”[4] or that “Knox’s findings should
be seriously taken into account by decision makers concerned with
environmental emissions’ limits and control” [3]. On the contrary, these
reports clearly indicate the dangers of conducting epidemiological
research without a proper comparison group and sound exposure assessment
methodology, and the need to challenge arguments that are presented with
no supporting evidence.
Competing interests: The author provides consultancy services to a
range of customers including the chemical industry. The author reviewed
these publications on behalf of the Lower Olefins sector group of the
European Chemical Industry Council (Cefic). However, the opinions
expressed in the letter are entirely those of the author.
References:
1. Knox EG. Childhood cancers and atmospheric carcinogens.
J Epidemiol Community Health. 2005;59:101-5.
2. Knox EG. Oil combustion and childhood cancers.
J Epidemiol Community Health. 2005;59:755-60.
3. Garcia AM, Alvarez-Dardet C. A journal for evidence based
policies. J Epidemiol Community Health. 2005;59:716-7.
4. Kogevinas M, Pearce N. Geographically based approaches can
identify environmental causes of disease. J Epidemiol Community Health.
2005;59:717-8.
This study showed a nice way to estimate income level.[1] However in
the paper it stated that there was a 24% changed of the increased risk
among unskilled workers after “adjusting for GHI”—(1.55-1.42)/(1.55-1)=0.236, if estimating in the same way, the difference between the lower
cut off point of the “CI”—1.24 and the point estimated hazard ratio—1.55
is (1.55-1.24)/0.55=56% of “the increased risk”,(...
This study showed a nice way to estimate income level.[1] However in
the paper it stated that there was a 24% changed of the increased risk
among unskilled workers after “adjusting for GHI”—(1.55-1.42)/(1.55-1)=0.236, if estimating in the same way, the difference between the lower
cut off point of the “CI”—1.24 and the point estimated hazard ratio—1.55
is (1.55-1.24)/0.55=56% of “the increased risk”,(data from table 3)[1] and
therefore it may not be suitable to consider there is a “real” reduction
in the “increased risk” as the reduction is much less than 56% of the
“increased risk”. Nevertheless if there was an effect of income on the
risk of MI that was unrelated to occupation, an effect of income might be
observed within the same occupation category.
Moreover when family income is also being investigated, it is
possible that the occupation of other family members may play an important
role on both of the family income and the life style of the family, and
further “link” income with “MI” risk.
Reference:
1. Andersen, I., et al., Income as mediator of the effect of
occupation on the risk of myocardial infarction: does the income
measurement matter? J Epidemiol Community Health, 2005. 59(12): p.1080-5.
The idea that the diseases of the future will increasingly have their
aetiological roots in 'comfort' is at first sight an appealing and
powerful one. However, to accept this idea uncritically could in fact be
part of the problem. Just to take one example for brevity: the idea that
everyone desperately wants to confine themselves to moving around in a
motor car. I often have arguments with people who cl...
The idea that the diseases of the future will increasingly have their
aetiological roots in 'comfort' is at first sight an appealing and
powerful one. However, to accept this idea uncritically could in fact be
part of the problem. Just to take one example for brevity: the idea that
everyone desperately wants to confine themselves to moving around in a
motor car. I often have arguments with people who claim that the car is a
precious guarantor of 'freedom'. One thing that argues against this is the
difference in the effects on the prices of houses when it is proposed to
build a road nearby versus what happens when improvements in local public
transport take place. In the former case, house prices plummet. In the
latter case, they generally tend to shoot upwards. In this way the market
gives us a clear signal about preferences if people are really given a
choice. The type of 'comfort' disease that arises from our ever
diminishing levels of exercise is in part the result of an unholy alliance
between the oil and motor vehicle industries, and governments who would
rather not deal with unionised skilled labour forces needed to run
transport systems. A furtive privatisation of transportation, by cutting
services and forcing people into cars, took place long before what was
left was officially privatised. A recent ONS report shows that households
now spend on average over £50 per week on their motor cars, one of most
expensive items in overall living costs, and around 1/3 of the total
guaranteed income level for pensioner households. So I do not really think
the pervasiveness of the car can be regarded in any simple way as the
result of the human attachment to comfort.
I agree with the paper that high unemployment rate may have a
negative impact on the health of the general population, as sickness
absence could be consider as a measure of health.[1] It may worthwhile to
further investigate the character of morbidity that associated with
economy hardship.
Nevertheless, the subjects in the paper were “entire staff of 10
towns and 15 public hospitals in 25 s...
I agree with the paper that high unemployment rate may have a
negative impact on the health of the general population, as sickness
absence could be consider as a measure of health.[1] It may worthwhile to
further investigate the character of morbidity that associated with
economy hardship.
Nevertheless, the subjects in the paper were “entire staff of 10
towns and 15 public hospitals in 25 separate areas”. Thus subjects could
be considered to be collected from several geographical clusters, and
people’s health in the same hospital could be strongly related. For
example, a small flu spreading among staff in some hospitals may affect
the incidence of “medically Certified sickness absence” in one “Local
unemployment rate “ strata greatly. However the cloud could be cleared, if
the original data showed no great variation of “medically Certified
sickness absence” incidence in different hospitals/ “municipal sectors”,
which are within the same “Local unemployment rate” strata.
Reference:
1. Virtanen, M., et al., Local economy and sickness absence:
prospective cohort study. J Epidemiol Community Health, 2005. 59(11): 973-8.
As a reader, I found the paper[1] interesting, and I hope that the
authors could provide extra information. In table 2, there were about one
third of participants did not answer their income level in all the three
area “SES” strata, However “Occupation” and “Education” may be associated
with income level in the same way among all the participants. So the
association between “Education”, “Occupation...
As a reader, I found the paper[1] interesting, and I hope that the
authors could provide extra information. In table 2, there were about one
third of participants did not answer their income level in all the three
area “SES” strata, However “Occupation” and “Education” may be associated
with income level in the same way among all the participants. So the
association between “Education”, “Occupation” and income level among
people who reported their income, could be applied to predict or gain more
information on the income level among people, who had provided information
on their “Education”, “Occupation” but not on their income level. (Chi-
Square test showed that the proportion of people who did not answer their
income were significant associated with area “SES”)
People are likely to choose a place to live according to their life
style, therefore people who are able to choose their living area, may
choose a place that meets their physical activities needs, and people who
have high income but choose a place not convenience for physical
activities, may not like physical activities at all. However this possible
confounder could be reduced by restricting the analysis to subjects who
were unlikely to be able to choose a place to live, for example, those who
are young or those who are in low income. These may lead to a large “CI”,
but the mean of “OR” could be considered as a “point estimation”.
Reference:
1. Kavanagh, A.M., et al., Urban area disadvantage and physical
activity: a multilevel study in Melbourne, Australia. J Epidemiol
Community Health, 2005. 59(11): p. 934-940.
The article by Bradley & McKelvey (1) calls for integration of
primary care and public health through General practitioners with special
interests (GPwSI) in public health. The authors seem to suggest that this
would be a novel idea for integration of primary care and public health.
Although, it may be a new idea elsewhere in the UK, in Walsall this
integration is already in place. The people of Wa...
The article by Bradley & McKelvey (1) calls for integration of
primary care and public health through General practitioners with special
interests (GPwSI) in public health. The authors seem to suggest that this
would be a novel idea for integration of primary care and public health.
Although, it may be a new idea elsewhere in the UK, in Walsall this
integration is already in place. The people of Walsall have perceived the
benefits of such integration.
There are 131 GPs in Walsall of which 23 are GPwSI. Sixteen out these
23 are working in areas concerning public health or public health related
issues. The key work that has been done and still ongoing, are in the
fields of substance abuse (5 GPwSI), CHD (5 GPwSI), Mental health, cancer,
palliative care, prescribing, NSF children and NSF diabetes (one each).
The highlights of this joint working have been the development of diabetes
guidelines for primary care, highest prescription of statins in Walsall,
increased provision of shared care for substance misuse and development of
protocol for suicide prevention. There has been a reduction in the death
rates due to CHD and Walsall in well on track to meet the target for 2010.
All GPwSI are accountable to the Director of Public Health and they
receive funding for their special interest work by the Primary Care Trust.
This reflects the organisational support, which the authors highlight as a
challenge.
The authors also suggest integrated primary care and public health
services in developing countries and give the example of Tanzania. We
would also like to highlight that in countries like India, public health
is indeed delivered by primary care providers. The medical officers of
health in the primary health centres are responsible for providing an
integrated preventive, promotive, curative and rehabilitative health care
to its clients.
Hence, we are of the opinion that integration of public health and
primary care through GPwSI in public health is the way forward and what
ever is the model of integration results are going to be beneficial as
evidenced by Walsall’s success story.
Reference
1. Bradley S and McKelvey SD. General practitioners with a special
interest in public health; at last a way to deliver public health in
primary care. J Epidemiol Community health November 2005; 11: 920-3
Dear Editor,
Thank you for your interest in our article.[1] In our opinion, your comment, that gross household income (GHI) changed 24% of the increased risk among unskilled workers is not a real change, does not take into account that the two analyses are dependent. (Table 3, the two first columns). If the Hazard Ratio was 1.24 (the lower limit of th...
Dear Editor,
Estimating the economic impact of ill health and the cost- benefit, and cost effectiveness, of interventions intended to reduce it, is an important but difficult exercise. The thoughtful paper by Rayner and Scarborough is to be welcomed as a serious attempt to quantify one aspect of this calculation: the direct costs to the NHS of treatment arising from the proportion of certain diseases attributabl...
Dear Editor,
I most certainly agree with the “reviewer’ comments” cited by the authors in the text of their paper; “The paper is timely and can be potentially useful for health policy makers” (p. 1032). However, “timely” in this case is a bit of an oddity. In response to a recent critique of progress that I had written (Betts, 2005) a rather noted philosopher, who is kind enough to review scholarly work for me fro...
Dear Editor,
This is a response to the e-letter sent by Dr Wenbin Liang. We appreciate the comments and found them highly valuable.
Point 1. "The subjects of the study are collected from several geographical clusters, and peoples health in the same hospital could be strongly related....A small flu spreading among staff may affect the incidence of medically certified sickness absence in one local emp...
Dear Editor,
The Journal of Epidemiology and Community Health has recently published two papers by Knox[1,2] which conclude that “childhood cancers are strongly determined by prenatal or early postnatal exposures to oil based combustion gases especially from engine exhausts. 1,3-butadiene, a known carcinogen, may be directly causal”. This is a strong conclusion for a study whose novel analysis uses only the birth...
Dear Editor,
This study showed a nice way to estimate income level.[1] However in the paper it stated that there was a 24% changed of the increased risk among unskilled workers after “adjusting for GHI”—(1.55-1.42)/(1.55-1)=0.236, if estimating in the same way, the difference between the lower cut off point of the “CI”—1.24 and the point estimated hazard ratio—1.55 is (1.55-1.24)/0.55=56% of “the increased risk”,(...
Dear Editor,
The idea that the diseases of the future will increasingly have their aetiological roots in 'comfort' is at first sight an appealing and powerful one. However, to accept this idea uncritically could in fact be part of the problem. Just to take one example for brevity: the idea that everyone desperately wants to confine themselves to moving around in a motor car. I often have arguments with people who cl...
Dear Editor,
I agree with the paper that high unemployment rate may have a negative impact on the health of the general population, as sickness absence could be consider as a measure of health.[1] It may worthwhile to further investigate the character of morbidity that associated with economy hardship.
Nevertheless, the subjects in the paper were “entire staff of 10 towns and 15 public hospitals in 25 s...
Dear Editor,
As a reader, I found the paper[1] interesting, and I hope that the authors could provide extra information. In table 2, there were about one third of participants did not answer their income level in all the three area “SES” strata, However “Occupation” and “Education” may be associated with income level in the same way among all the participants. So the association between “Education”, “Occupation...
Dear Editor
The article by Bradley & McKelvey (1) calls for integration of primary care and public health through General practitioners with special interests (GPwSI) in public health. The authors seem to suggest that this would be a novel idea for integration of primary care and public health. Although, it may be a new idea elsewhere in the UK, in Walsall this integration is already in place. The people of Wa...
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