Thank you for this interesting analysis of scientific productivity in
Africa.
There are a couple of things that are not entirely correct, however.
I don't think this is the only citation analysis covering Africa
published in this millennium. For example, you may have overlooked an
analysis of epidemiological citations per population published in 2012
(International Journal of Epidemiology 41:579-588)....
Thank you for this interesting analysis of scientific productivity in
Africa.
There are a couple of things that are not entirely correct, however.
I don't think this is the only citation analysis covering Africa
published in this millennium. For example, you may have overlooked an
analysis of epidemiological citations per population published in 2012
(International Journal of Epidemiology 41:579-588).
Your Figure 1 is also difficult to understand. A "quintile" is a
group that contains one-fifth of the observations, ranked by the variable
of interest. You only show four quintiles, which is therefore a
contradiction in terms, and there is not an equal number of countries in
each quintile.
Recently a paper by Rachiotis et al [1] suggested that suicide rates
in Greece rose after 2010 and that unemployment is the crucial etiologic
factor.
A number of significant comments are important concerning the above.
The selectivity of the literature these authors review is impressive,
especially concerning the literature on the suicidal rates of Greece.
First of all, these results are by no means new. It ha...
Recently a paper by Rachiotis et al [1] suggested that suicide rates
in Greece rose after 2010 and that unemployment is the crucial etiologic
factor.
A number of significant comments are important concerning the above.
The selectivity of the literature these authors review is impressive,
especially concerning the literature on the suicidal rates of Greece.
First of all, these results are by no means new. It has already been
reported by our group with the specific conclusion that only after 2010 a
rise in suicides is clearly visible [2-5] while, on the contrary, the
authors of the paper under discussion have repeatedly suggested it started
already after 2007 [6-10]. We are pleased that our conclusions are finally
adopted by other research groups although they seem to present them as
novel in the literature.
The second issue is on causality. The detailed inspection of age and
gender specific rates suggests that for males the increase in suicidal
rates is present in all age groups except <14, 25-29, and >80. For
females the increase is also present in all age groups except 40-54 and 65
-69. However, and this is of outmost importance, the greatest increase in
the rates from 2003-2010 in comparison to 2011-2 is seen in females aged
15-19 (149.18%), 20-24 (148.65%), 35-39 (86.24%) and 55-59 (60.74%). In
comparison the highest rate for males was seen in the age group 55-59
(61%). These results are not in accord with a male gender by unemployment
interaction.
For the years 1981-2012 the correlation of male suicidal rate to
unemployment is 0.54 but for 1981-2010 is -0.09, suggesting that there is
no linear relationship. The chart of unemployment and male suicidal rates
from 1981-2012 (can not be presented here) clearly shows that it is very
difficult to decide when suicides started increasing. Three time points
are possible and these are the years 2003, 2007 and 2010, depending on the
interpretation of the pattern.
In previous publications of these authors, the assumption that
unemployment is responsible for the rise in the suicide rates is strongly
supported. However, two recently published papers by a large group of
international researchers clearly disputes the assumption that
specifically the changes in unemployment have a direct effect on suicidal
rates [11 12]. The temporal sequence and correlation of events (suicides
rise first, economic recession follows, synchronization of suicidal rate
changes across the continent) suggests there is a close relationship
between the economic environment and suicidal rates; however this
relationship is not that of a direct cause and effect. This seems to be
true for US also since in spite of claims that the rise in unemployment
caused a rise of the suicide rate in the US [13], a closer look at the
data revealed that also in the US suicides raised first and unemployment
followed [3]. The Hungarian data present with a similar picture also [14].
One could argue that those people who are going to lose their jobs
are stressed months before this happens, but 'fear' of unemployment is
quite different from unemployment per se, especially since such an
assumption suggests that employed people do commit suicide before they
become unemployed. Since the rise in suicides also affects prospering
countries without high unemployment, including Germany and Norway, another
possible explanation is that the changes in the socioeconomic environment
and especially in the employment conditions (e.g. flexible employment,
more rigid rules) which are now in place almost in every country
irrespective of its economic status, have overstressed vulnerable
populations (e.g. mental patients). If this is so, prosperity in general
will not bring a fall in the suicide rates unless it is accompanied by
targeted interventions to support these vulnerable groups which are
disproportionally stress by recession. Increased suicide rates are
probably a consequence of this disproportionate stress.
Overall, the authors of the paper under discussion here [1] chose to
discuss the literature in an impressively ignoring and biased way, which
essentially precluded the discussion of an existing and important argument
concerning the relationship of unemployment with suicidality. Interpreting
data in different ways is legitimate and part of the scientific method and
practice; ignoring and hidding parts of the literature is problematic.
Funding:
This research received no specific grant from any funding agency in the
public, commercial, or not-for-profit sectors.
References:
1. Rachiotis G, Stuckler D, McKee M, et al. What has happened to
suicides during the Greek economic crisis? Findings from an ecological
study of suicides and their determinants (2003-2012). BMJ open
2015;5(3):e007295 doi: 10.1136/bmjopen-2014-007295[published Online First:
Epub Date]|.
2. Fountoulakis KN, Koupidis SA, Grammatikopoulos IA, et al. First
reliable data suggest a possible increase in suicides in Greece. Bmj
2013;347:f4900 doi: 10.1136/bmj.f4900[published Online First: Epub Date]|.
3. Fountoulakis KN, Koupidis SA, Siamouli M, et al. Suicide,
recession, and unemployment. Lancet 2013;381(9868):721-2 doi:
10.1016/S0140-6736(13)60573-5[published Online First: Epub Date]|.
4. Fountoulakis KN, Savopoulos C, Siamouli M, et al. Trends in
suicidality amid the economic crisis in Greece. European archives of
psychiatry and clinical neuroscience 2013;263(5):441-4 doi: 10.1007/s00406
-012-0385-9[published Online First: Epub Date]|.
5. Fountoulakis KN, Siamouli M, Grammatikopoulos IA, et al. Economic
crisis-related increased suicidality in Greece and Italy: a premature
overinterpretation. Journal of epidemiology and community health
2013;67(4):379-80 doi: 10.1136/jech-2012-201902[published Online First:
Epub Date]|.
6. Kentikelenis A, Karanikolos M, Reeves A, et al. Greece's health
crisis: from austerity to denialism. Lancet 2014;383(9918):748-53 doi:
10.1016/S0140-6736(13)62291-6[published Online First: Epub Date]|.
7. Chang SS, Stuckler D, Yip P, et al. Impact of 2008 global economic
crisis on suicide: time trend study in 54 countries. Bmj 2013;347:f5239
doi: 10.1136/bmj.f5239[published Online First: Epub Date]|.
8. Karanikolos M, Mladovsky P, Cylus J, et al. Financial crisis,
austerity, and health in Europe. Lancet 2013;381(9874):1323-31 doi:
10.1016/S0140-6736(13)60102-6[published Online First: Epub Date]|.
9. De Vogli R, Marmot M, Stuckler D. Strong evidence that the
economic crisis caused a rise in suicides in Europe: the need for social
protection. Journal of epidemiology and community health 2013;67(4):298
doi: 10.1136/jech-2012-202112[published Online First: Epub Date]|.
10. Stuckler D, Basu S, Suhrcke M, et al. Effects of the 2008
recession on health: a first look at European data. Lancet
2011;378(9786):124-5 doi: 10.1016/S0140-6736(11)61079-9[published Online
First: Epub Date]|.
11. Nordt C, Warnke I, Seifritz E, et al. Modelling suicide and
unemployment: a longitudinal analysis covering 63 countries, 2000-11.
Lancet Psychiatry 2015
12. Fountoulakis KN, Kawohl W, Theodorakis PN, et al. Relationship of
suicide rates to economic variables in Europe: 2000-2011. The British
journal of psychiatry : the journal of mental science 2014 doi:
10.1192/bjp.bp.114.147454[published Online First: Epub Date]|.
13. Reeves A, Stuckler D, McKee M, et al. Increase in state suicide
rates in the USA during economic recession. Lancet 2012;380(9856):1813-4
doi: 10.1016/S0140-6736(12)61910-2S0140-6736(12)61910-2 [pii][published
Online First: Epub Date]|.
14. Fountoulakis KN, Gonda X, Dome P, et al. Possible delayed effect
of unemployment on suicidal rates: the case of Hungary. Annals of general
psychiatry 2014;13:12 doi: 10.1186/1744-859X-13-12[published Online First:
Epub Date]|.
Flying is safe, and health care is dangerous-why?
Prior to 1977, the airline industry ran quality improvement and pilot oversight as medicine does now, using the "Captain of the Ship" model, presuming that quality was to be had by making pilots better and better so they were infallible (and blaming 'pilot error' for bad outcomes.) At Tenerife, KLM's head 747 instructor and head of their safety program made an error, along with o...
Flying is safe, and health care is dangerous-why?
Prior to 1977, the airline industry ran quality improvement and pilot oversight as medicine does now, using the "Captain of the Ship" model, presuming that quality was to be had by making pilots better and better so they were infallible (and blaming 'pilot error' for bad outcomes.) At Tenerife, KLM's head 747 instructor and head of their safety program made an error, along with other errors that day. http://www.desastresaereos.net/ft_trag_ten_acidentetenerife3.jpg
The airlines changed their approach to safety and designed resilient systems to catch and prevent errors, instead of blaming people for mistakes. (Punishment was moot, as most erring pilots died with their planes.) Doing the wrong things better, (e.g., current physician review) helps no one, so medicine has the equivalent of hundreds of Tenerife events a year. They happen one life at a time, so don't have the shock value of 3/27/77.
Designing all our systems to prevent and correct errors would save lives and careers. When will we learn?
Thanks Peter for having interest in our bibliometric analysis1 and for your comments. Wholeheartedly agreed, our bibliometric analysis[1] is not the only citation analysis covering Africa, published in this millennium. We have not overlooked the other citation analysis[2]. There are excellent Africa-focused subject-specific citation analyses from our group and others[3-10]. However, we would like to point that the focus of this ci...
Thanks Peter for having interest in our bibliometric analysis1 and for your comments. Wholeheartedly agreed, our bibliometric analysis[1] is not the only citation analysis covering Africa, published in this millennium. We have not overlooked the other citation analysis[2]. There are excellent Africa-focused subject-specific citation analyses from our group and others[3-10]. However, we would like to point that the focus of this citation analysis was not to examine or review existing citation analyses, but rather to describe and examine factors associated with research productivity of first authors based in African institutions using articles indexed in PubMed as a surrogate.
The word "quintile" should have been written as 'quartiles', this was a typographical error. The countries were categorised into four groups and not five groups. As stated in the results section [1]: "Eighteen countries occupy the highest quartile with more than 1000 articles each. Ten countries belong to the second quartile (i.e. 500-999 articles) and 13 to the third quartile (100-499 articles). Five countries with less than 100 articles each belong to the lowest quartile." This adds up to 46 countries, which is the number of countries included in the citation analysis. The list of the 46 countries is provided in the online only Supplementary Data [1]. On a final note, this typographical error does not change the results nor does it change the conclusions of our citation analysis[1].
Olalekan A. Uthman
1. Centre for Evidence-based Health Care, Faculty of Medicine and Health Sciences, Stellenbosch University, Francie van Zijl Drive, Cape Town, 7505, South Africa
2. Warwick-Centre for Applied Health Research and Delivery (WCAHRD), University of Warwick, Warwick Medical School, Gibbet Hill Rd, Coventry, CV4 7AL, UK
Charles S. Wiysonge
1. Centre for Evidence-based Health Care, Faculty of Medicine and Health Sciences, Stellenbosch University, Francie van Zijl Drive, Cape Town, 7505, South Africa
2. South African Cochrane Centre, South African Medical Research Council, Francie van Zijl Drive, Cape Town, 7505, South Africa
References
1. Uthman OA, Wiysonge CS, Ota MO, et al. Increasing the value of health research in the WHO African Region beyond 2015--reflecting on the past, celebrating the present and building the future: a bibliometric analysis. BMJ Open 2015;5(3):e006340.
2. Sankoh O, Byass P. The INDEPTH Network: filling vital gaps in global epidemiology. Int J Epidemiol 2012;41(3):579-88.
3. Uthman OA, Uthman MB. Geography of Africa biomedical publications: an analysis of 1996-2005 PubMed papers. Int J Health Geogr 2007;6:46.
4. Uthman OA. HIV/AIDS in Nigeria: a bibliometric analysis. BMC Infect Dis 2008;8:19.
5. Uthman OA. Pattern and determinants of HIV research productivity in sub-Saharan Africa: bibliometric analysis of 1981 to 2009 PubMed papers. BMC Infect Dis 2010;10:47.
6. Chen JY, Ribaudo HJ, Souda S, et al. Highly active antiretroviral therapy and adverse birth outcomes among HIV-infected women in Botswana. J Infect Dis 2012;206(11):1695-705.
7. Kanoute A, Faye D, Bourgeois D. Current status of oral health research in Africa: an overview. Int Dent J 2012;62(6):301-7.
8. Nachega JB, Uthman OA, Ho YS, et al. Current status and future prospects of epidemiology and public health training and research in the WHO African region. Int J Epidemiol 2012;41(6):1829-46.
9. Wiysonge CS, Uthman OA, Ndumbe PM, et al. A bibliometric analysis of childhood immunization research productivity in Africa since the onset of the Expanded Program on Immunization in 1974. BMC Med 2013;11:66.
10. Bloomfield GS, Baldridge A, Agarwal A, et al. Disparities in cardiovascular research output and citations from 52 african countries: a time-trend, bibliometric analysis (1999-2008). J Am Heart Assoc 2015;4(4).
Radical austerity and unemployment are associated with increased suicide mortality in Greece.
George Rachiotis1, David Stuckler2,3 Martin McKee34, Christos Hadjichristodoulou1.
1.Department of Hygiene and Epidemiology, Medical Faculty, School of Health Science, University of Thessaly, Larissa, Greece
2.Department of Sociology, University of Oxford, Oxford, UK
3.European Centre on Health of Societies in Transition, London School o...
Radical austerity and unemployment are associated with increased suicide mortality in Greece.
George Rachiotis1, David Stuckler2,3 Martin McKee34, Christos Hadjichristodoulou1.
1.Department of Hygiene and Epidemiology, Medical Faculty, School of Health Science, University of Thessaly, Larissa, Greece
2.Department of Sociology, University of Oxford, Oxford, UK
3.European Centre on Health of Societies in Transition, London School of Hygiene and Tropical Medicine, London, UK
4.European Observatory on Health Systems and Policies, London, UK
We would like to thank researchers and readers of the journal for their interest in our paper [1]. Dr Fountoulakis, in his reply, [2] accused us of selectivity of citation, insisting that the increase in suicides after 2010 has been already reported by him and co-workers [3-6]. Remarkably, three out of 4 references that Dr Fountoulakis mentioned are totally irrelevant to analysis of suicides in Greece after 2010 [3-5]. Surprisingly, in a short communication about suicidality in Greece in the period 2000-2010, the authors stated that:'' The results of the current study suggest no increase in suicidality in Greece during the recent economic crisis...'' [4]. In one of the references mentioned by Dr Fountoulakis [6] there is a statement that the absolute number of suicides in Greece increased in 2011, but data for 2012 were not reported. We did not mention this letter to the editor -which refers to only one year- given that the description of a trend was impossible. Regarding age and gender specific rates, we feel that the use of numerous age groups in the analysis of suicides creates the problems associated with of small numbers of observations. On the contrary our analysis (with 3 large age groups) provides the reader with a clearer picture of the impact of unemployment on suicides, especially among males of working ages. At this point we note that there was a significant correlation between unemployment rates and suicide mortality among males of working age. On the contrary this was not the case for females, despite the observed increase in suicide rates among them. Dr Fountoulakis denied that male suicide rates are common, but the data suggest a 34% increase in male suicide rate in 2011-2012. The increase among females of working age during the same period was lower (25.5%) although considerable. The previous data confirmed a key role for male gender in increased suicide rates in Greece and are consistent with previous published information [7].
Dr Fountoulakis missed the point regarding the significance of 2010 in relation to the radical austerity policies. The fact that, as Dr Fountoulakis stated, the correlation of male suicide rates with unemployment changed, within two years, from 2011 to 2012, from -0.09 to 0.54 is indicative of the strong and independent impact of radical austerity on male suicide rates in Greece. Unfortunately, this documented impact has been consistently ignored by Dr Fountoulakis.
Further, we note that Dr Fountoulakis ignored the results by many independent research teams from Greece and abroad regarding a positive correlation between unemployment and suicide rates in Greece [8-10]. In addition he failed to mention that an increase in suicide rates was associated with austerity policies in Greece [11]. Regarding the temporal association between unemployment and suicide rates in Greece, the facts are quite clear. The general trend indicates-at least after 2009 and among males- that unemployment increased and the suicide rates increased afterwards. Dr Fountoulakis failed to explain the nature of the program imposed to Greece by the Troika from 2010. This program refers to a ''shock therapy'' very similar to that implemented in Russian Federation during the 90's. The Greek economy shrank by 25% between 2008-2012 and the unemployment rate doubled from 12.7% in 2010 to 24% in 2012. These figures indicate an unprecedented, at least since World War II, radical experiment in socio-economic destruction and welfare-state retrenchment in Europe.
We have pointed out the harmful consequences of continuing delays in publishing mortality data [1]. These delays mean that it will not be possible to bring the story of economic crisis and suicides completely up to date. Indeed, in our analysis we had available data only for the first two years (2011 and 2012) of the implementation of radical austerity in Greece. Nevertheless, these data provide preliminary evidence that radical austerity is associated with increased suicides in Greece, although there are several possible mechanisms by which austerity may act.
It is a positive sign that the President of European Commission Jean Claude Juncker recently recognized the ongoing humanitarian crisis in Greece [12]. However, there is an urgent need to undertake a comprehensive health impact assessment of the radical austerity imposed by the Troika, in line with the obligation placed on the European institutions by the European Treaties [13].
References:
1. Rachiotis G, Stuckler D, McKee M, et al. What has happened to suicides during the Greek economic crisis? Findings from an ecological study of suicides and their determinants (2003-2012). BMJ open 2015;5(3):e007295 doi: 10.1136/bmjopen-2014-007295[published Online First: Epub Date]|.
2. Fountoulakis KN. Reply to Rachiotis et al: Increased unemployment might not be the cause of the world wide rise in suicide rates. BMJ Open, April 23, 2015; e-letter
3. Fountoulakis KN, Koupidis SA, Siamouli M, et al. Suicide, recession, and unemployment. Lancet 2013;381(9868):721-2 doi: 10.1016/S0140-6736(13)60573-5[published Online First: Epub Date]|.
4. Fountoulakis KN, Savopoulos C, Siamouli M, et al. Trends in suicidality amid the economic crisis in Greece. European archives of psychiatry and clinical neuroscience 2013;263(5):441-4 doi: 10.1007/s00406 -012-0385-9[published Online First: Epub Date]|.
5. Fountoulakis KN, Siamouli M, Grammatikopoulos IA, et al. Economic crisis-related increased suicidality in Greece and Italy: a premature overinterpretation. Journal of epidemiology and community health 2013;67(4):379-80 doi: 10.1136/jech-2012-201902[published Online First: Epub Date]|.
6. Fountoulakis KN, Koupidis SA, Grammatikopoulos IA, et al. First reliable data suggest a possible increase in suicides in Greece. Bmj 2013;347:f4900 doi: 10.1136/bmj.f4900[published Online First: Epub Date]|.
7. Kentikelenis A, Karanikolos M, Reeves A et al. Greece's health crisis: from austerity to denialism. Lancet 2014;383:748-53.
8. Kontaxakis V, Papaslanis T, Havaki-Kontaxaki B et al. Suicide in Greece: 2001-2011. Psychiatrike. 2013;2:170-4.
9. Madianos MG, Alexiou T, Patelakis A et al. Suicide, unemployment and other socioeconomicfactors: evidence from the economic crisis in Greece. Eur J Psychiat 2014;28:39-49.
10. Antonakakis N, Collins A. The impact of fiscal austerity on suicide: on the empirics of a modern Greek tragedy. Soc Sci Med. 2014;112:39-50. doi: 10.1016/j.socscimed.2014.04.019. Epub 2014 Apr 19.
11. Branas CC, Kastanaki AE, Michalodimitrakis M et al. The impact of economic austerity and prosperity events on suicide in Greece: a 30-year interrupted time-series analysis. BMJ Open. 2015;5:e005619. doi: 10.1136/bmjopen-2014-005619.
12. EU's Junker pledges 2bn euros for Greek ''humanitarian crisis''. BBC News. 20 March 2015.
13. McKee M, Karanikolos M, Belcher P et al. Austerity: a failed experiment on the people of Europe. Clinical Medicine 2012;12:346-50.
Thank you for a well presented article.
We would like to highlight a few aspects that we found in the literature
related to the subject and subsequently would like to convey our opinions.
Alcoholism and other addictions have genetic and environmental causes.
Both have serious consequences for children who live in homes where
parents are involved. Children of addicted parents are the highest risk
group of children to beco...
Thank you for a well presented article.
We would like to highlight a few aspects that we found in the literature
related to the subject and subsequently would like to convey our opinions.
Alcoholism and other addictions have genetic and environmental causes.
Both have serious consequences for children who live in homes where
parents are involved. Children of addicted parents are the highest risk
group of children to become alcohol and drug abusers due to both genetic
and family environment factors1.
Biological children of alcohol dependent parents who have been adopted
continue to have an increased risk (2-9 fold) of developing alcoholism.2
Adolescent alcohol use, especially heavy use, is associated with many
negative outcomes. It has been found that alcohol dependent adolescents
have poorer neuropsychological performance and are more sensitive to
learning and memory impairments produced by alcohol exposure. Adolescent
alcohol use may interfere with the development of social, coping, and
related skills needed for effective social functioning in late adolescence
and early adulthood. Children who coped effectively with the trauma of
growing up in families affected by alcoholism often relied on the support
of a non-alcoholic parent, stepparent, grandparent, teachers and others.3
Our opinion apart from those presented in the referenced literature above
would be that beyond the socio-cultural and genetic aspects covered in
different articles , there is an element of parental responsibility and
parental monitoring which needs to be taken into account when it comes to
alcohol and substance misuse in the adolescent population .
We also feel that there is an argument for parenting styles and parental
monitoring as the manner in which boundaries are set and the individual
young person's needs met, could be a crucial element in determining the
young person's potential subsequent involvement and or reliance on drugs,
alcohol and other mind altering substances. Family conflicts , domestic
violence , social isolation ,financial problems are only a few other
contributing factors which need to be accounted for when one considers the
association between parental roles and adolescent drinking behaviour .
References:
1. Kumpfer, K.L. (1999). Outcome measures of interventions in the study of
children of substance-abusing parents. Paediatrics. Supplement. 103 (5):
1128-1144.
2. Schuckit, M.A., Goodwin, D.A., & Winokur, G. (1972). A study of
alcoholism in half siblings. American Journal of Psychiatry, 128: 1132-
1136
3. Brown, S., & Tapert, S. (2004). Adolescence and the trajectory of
alcohol use: Basic to clinical studies. Annals of the New York Academy of
Sciences, 1021, 234-244.
Re: A nomogram to estimate the HbA1c response to different DPP-4
inhibitors in type 2 diabetes: a systematic review and meta-analysis of 98
trials with 24 163 patients. Esposito, et al. 5:2 e005892
doi:10.1136/bmjopen-2014-005892
We read with interest the recent article by Esposito et al.
describing their development of a nomogram to predict HbA1c response to
different dipeptidyl peptidase (DPP)-4 inhibitors in...
Re: A nomogram to estimate the HbA1c response to different DPP-4
inhibitors in type 2 diabetes: a systematic review and meta-analysis of 98
trials with 24 163 patients. Esposito, et al. 5:2 e005892
doi:10.1136/bmjopen-2014-005892
We read with interest the recent article by Esposito et al.
describing their development of a nomogram to predict HbA1c response to
different dipeptidyl peptidase (DPP)-4 inhibitors in the treatment of type
2 diabetes (1). We believe that several important factors need to be
considered when interpreting the results of this study.
Firstly, the nomogram was derived from a meta-regression model
relating treatment effect to several covariates, including baseline HbA1c
level, type of DPP-4 inhibitor and baseline fasting plasma glucose. Other
covariates were tested but found to not have additional effects - although
background medication was included only as a binary variable, and
therefore the treatment effect of different types of medication may not
have been captured. Importantly, however, the authors did not further test
additional covariates likely to affect treatment response - notably,
length of prior drug washout, diabetes duration and race/ethnicity.
Regarding the latter, for example, there is evidence that the efficacy of
DPP-4 inhibitors is greater in Asians than in Caucasians (2)(3).
One particularly notable limitation of the model is the use of
absolute HbA1c changes rather than the placebo-corrected values that are
conventionally used in meta-analyses. The authors acknowledge this
limitation without fully justifying it. Unfortunately, the use of absolute
HbA1c changes without any adjustments can lead to inaccurate estimates of
the treatment effects of individual DPP-4 inhibitors. For example,
absolute changes in HbA1c in two of the studies included, both conducted
in Asian patients, were -0.24% and -1.05%, suggesting the drug in the
latter study (vildagliptin) to be more effective than that in the former
(linagliptin). However, the placebo-corrected changes were -0.87% with
linagliptin and -0.51% with vildagliptin (4)(5).
Additionally, the meta-regression model included baseline HbA1c as a
covariate. However, most, if not all, of the included studies reported
HbA1c changes from baseline derived from ANCOVA models that already
contained baseline HbA1c as a covariate.
As acknowledged by the authors, by far the strongest predictive
factor for HbA1c response was baseline HbA1c, with different DPP-4
inhibitors explaining only a small amount of variance between studies.
However, there was a significant residual variance in the meta-regression
model that could not be explained, and may reflect the potential
confounding factors discussed above.
In light of these limitations, the authors' statement that "[T]he
nomogram is not intended to give a comparison of different DPP-4
inhibitors, given the lack of head-to-head RCTs comparing their efficacy
in HbA1c reduction from baseline" seems incongruent with their concluding
sentence that "[T]he nomogram we developed may help clinicians in
predicting the HbA1c response to individual DPP-4 inhibitor [sic] in
clinical practice."
We also note that studies in patients with renal impairment were
excluded from the model. Given the high prevalence of chronic kidney
disease among patients with T2DM, estimated to be ~40% (6), this exclusion
could affect the external validity of the nomogram.
On the basis of these considerations, we conclude that Esposito et
al.'s nomogram - although an interesting and novel approach to predicting
HbA1c response to DPP-4 inhibitors - is likely to be confounded, and may
not provide an accurate estimate of the true treatment effects of
individual medications. Consequently, the nomogram should not be used to
compare clinical efficacy or real-world effectiveness between DPP-4
inhibitors, as the authors themselves note.
1. Esposito K, Chiodini P, Maiorino MI, et al. A nomogram to estimate
the HbA1c response to different DPP-4 inhibitors in type 2 diabetes: a
systematic review and meta-analysis of 98 trials with 24 163 patients. BMJ
Open 2015; 5: e005892. doi:10.1136/bmjopen-2014-005892.
2. Kim YG, Hahn S, Oh TJ, Kwak SH, Park KS, Cho YM. Differences in
the glucose-lowering efficacy of dipeptidyl peptidase-4 inhibitors between
Asians and non-Asians: a systematic review and meta-analysis. Diabetologia
2013; 56: 696-708.
3. Cai X, Han X, Luo Y, Ji L. Efficacy of dipeptidyl-peptidase-4
inhibitors and impact on beta-cell function in Asian and Caucasian type 2
diabetes mellitus patients: A meta-analysis. J Diabetes 2015; 7: 347-59.
4. Pan C, Xing X, Han P, et al. Efficacy and tolerability of
vildagliptin as add-on therapy to metformin in Chinese patients with type
2 diabetes mellitus. Diabetes Obes Metab 2012; 14: 737-744.
5. Kawamori R, Inagaki N, Araki E, et al. Linagliptin monotherapy
provides superior glycaemic control versus placebo or voglibose with
comparable safety in Japanese patients with type 2 diabetes: a randomized,
placebo and active comparator-controlled, double-blind study. Diabetes
Obes Metab 2012; 14: 348-357.
6. Koro CE, Lee BH, Bowlin SJ. Antidiabetic medication use and
prevalence of chronic kidney disease among patients with type 2 diabetes
mellitus in the United States. Clin Ther 2009; 31: 2608-2617.
Acknowledgements: Editorial assistance, supported financially by
Boehringer Ingelheim, was provided by Giles Brooke, PhD CMPP, of Envision
Scientific Solutions during the preparation of this letter.
Conflict of Interest:
All authors are employees of Boehringer Ingelheim Pharma GmbH & Co. KG (Ingelheim, Germany), the manufacturer of a DPP-4 inhibitor (linagliptin).
Title: Views on Condom effectiveness among adolescents in three Latin
American countries.
This research made great contribution as a stepping stone in comparing
safe sex and sexual risk behaviors in Latin American countries and by
extension Spain, however similar studies conducted in Kenya, Uganda and
South Africa revealed different levels on infection. Whereas the three
countries had prevalence of HIV for the general pop...
Title: Views on Condom effectiveness among adolescents in three Latin
American countries.
This research made great contribution as a stepping stone in comparing
safe sex and sexual risk behaviors in Latin American countries and by
extension Spain, however similar studies conducted in Kenya, Uganda and
South Africa revealed different levels on infection. Whereas the three
countries had prevalence of HIV for the general population below 1%,
conversely, the three sub-Saharan countries had HIV prevalence ranging
from 5.6% (MOH Kenya, 2014) ,7% in Uganda and an all time worrying 12.2%
South Africa respectfully. It is for this reason therefore, I could have
suggested having countries with similar or close prevalence rates ranked
together for a better comparison based on population dynamics and regional
diversity.
On safe sex belief, the research revealed that one out of seven adolescent
believed that condoms are 100% effective in the three Latin America
countries. As much as the results were appealing, a supplement article on
Epidemiology of HIV and AIDS Among Adolescents: Current Status,
Inequities, and Data Gaps indicated that knowledge in belief of condom
effectiveness and use among the adolescents in developing countries
remained low : HIV, AIDS, adolescents, prevention, care, treatment (J
Acquir et.al ,2014;66:S144-S153). Based on the above results, comparing
Kenya, Uganda and South Africa on the same parameters would less likely
yield the same results. This is because there are different factors
associated to condom use ranging from religious to cultural beliefs about
safe sex.
The paper also sought to find out whether the adolescents had had sex.
Adolescents who believed that condoms were 100% effective were 82% likely
to have had sex and used condoms. This was very good results if the paper
would have been able to truly prove of scientifically that they used
condoms. However, it is of crucial importance to note that early sexual
debut among adolescents begins before 15 years of age. There are several
researches showing significant variations of early sexual debut based on
different regions of the world. The paper ought to have put in
consideration the element of costs. Condoms access was not discussed in
the paper. In Kenya for example, Condoms are sold or placed in specific
dispensing points. Adolescents living in rural areas will either shy off
or feel ashamed to pick condoms where their relatives dine and wine.
Various reports indicate that where condoms are not available adolescents
either improvise small micron polythene papers for condoms or practice
unprotected sex. Adolescents also have tendency of using condoms at
initial contacts and discard their use later. These has shown considerable
rise in sexually transmitted infections as echoed by supplementary report
on Epidemiology of HIV and AIDS among adolescents (J Acquir et.al, 2014;
66:S144-S153). Condoms use cannot guarantee protection of infections i.e.
Herpes simplex and Human papilloma. This gives me a valid reason to say
that it is not safe for adolescents in sub-Saharan Africa with little
access to approve of its use.
In as much as I respect the research findings, Wood, in his work on
social cultural effects of HIV in South Africa wrote "Local understanding
of the gendered effects of sexual intercourse and lack of it on men causes
retention of semen which in turn is thought by many young South African
men to cause an array of undesirable effects, including
'madness'.(Wood,2002)".Based on the above, adolescents growing up in this
kind of settings will less likely use condoms because condoms may be
considered like a barrier causing madness. The adolescents do not live in
isolation, they operate and interaction in a society guided by cultural
norms, I therefore, highly doubt them going against the dictates of
cultural perception on condom use. When in doubt on condom information,
adolescents would frequently ask these questions to peers who may not have
befitting correct answers. His second finding was equally not possible to
measure but has detrimental effects on adolescents. He further wrote
"Women are said to have sexual appetites which are, again, thought to need
regulating as well as satisfying too frequent sex and too many partners
for women are considered to jeopardize vaginal tightness, which is
desirable because it is associated with 'heat', which is central to male
sexual pleasure (Wood, 2002)." Going by these findings revealing that
condoms are100% effective and ready to be used by the adolescents in Sub
Saharan Africa leaves me with many unanswered questions to our next
generation.
In spite of this inspiring work, the study in future may consider making
comparison of researches done in Latin America and sub-Saharan Africa to
inform on condom use as key prevention intervention among the adolescents.
By: Benjamin Macharia
The Lisbon Cohort of men who have sex with men (MSM) identified gays,
bisexuals and MSM aged between 20-29 years as key populations most
affected by HIV/AIDS1 and key contributors to the epidemic in Portugal.
The study identified the need to establish instruments for monitoring HIV
and syphilis incidence, determinants of infection and risk-taking
behaviors in MSM.
A community-based walk-in centre was used to recruit MSM a...
The Lisbon Cohort of men who have sex with men (MSM) identified gays,
bisexuals and MSM aged between 20-29 years as key populations most
affected by HIV/AIDS1 and key contributors to the epidemic in Portugal.
The study identified the need to establish instruments for monitoring HIV
and syphilis incidence, determinants of infection and risk-taking
behaviors in MSM.
A community-based walk-in centre was used to recruit MSM as participants
of a cohort study despite the obvious limitation of recruiting only men
that walked into the centre. Chinese and European studies recommended the
Internet as an effective avenue for recruiting study subjects, and other
authors have used formal health or academic institutions to recruit
participants2.
The article highlighted several cultural, anthropological and sociological
challenges in the conduct of community-based studies with MSM. The use of
community-based or Internet strategies for recruiting participants from
vulnerable populations such as MSM may be difficult in low-income
countries; this is related to the reality that MSM is still not accepted
in these countries. Conducting such a study in low-income settings may
yield evidence which may not be generalized across populations. However,
the Lisbon cohort provides a good foundation for researchers that would
like to conduct research around MSM in similar settings.
Thank you for this interesting analysis of scientific productivity in Africa.
There are a couple of things that are not entirely correct, however.
I don't think this is the only citation analysis covering Africa published in this millennium. For example, you may have overlooked an analysis of epidemiological citations per population published in 2012 (International Journal of Epidemiology 41:579-588)....
Recently a paper by Rachiotis et al [1] suggested that suicide rates in Greece rose after 2010 and that unemployment is the crucial etiologic factor.
A number of significant comments are important concerning the above. The selectivity of the literature these authors review is impressive, especially concerning the literature on the suicidal rates of Greece. First of all, these results are by no means new. It ha...
The full date set for this article can be found in Dryad.
Accessible here: http://datadryad.org/resource/doi:10.5061/dryad.8bv8p
Conflict of Interest:
None declared
Thank you for a well presented article. We would like to highlight a few aspects that we found in the literature related to the subject and subsequently would like to convey our opinions. Alcoholism and other addictions have genetic and environmental causes. Both have serious consequences for children who live in homes where parents are involved. Children of addicted parents are the highest risk group of children to beco...
Re: A nomogram to estimate the HbA1c response to different DPP-4 inhibitors in type 2 diabetes: a systematic review and meta-analysis of 98 trials with 24 163 patients. Esposito, et al. 5:2 e005892 doi:10.1136/bmjopen-2014-005892
We read with interest the recent article by Esposito et al. describing their development of a nomogram to predict HbA1c response to different dipeptidyl peptidase (DPP)-4 inhibitors in...
Title: Views on Condom effectiveness among adolescents in three Latin American countries. This research made great contribution as a stepping stone in comparing safe sex and sexual risk behaviors in Latin American countries and by extension Spain, however similar studies conducted in Kenya, Uganda and South Africa revealed different levels on infection. Whereas the three countries had prevalence of HIV for the general pop...
The Lisbon Cohort of men who have sex with men (MSM) identified gays, bisexuals and MSM aged between 20-29 years as key populations most affected by HIV/AIDS1 and key contributors to the epidemic in Portugal. The study identified the need to establish instruments for monitoring HIV and syphilis incidence, determinants of infection and risk-taking behaviors in MSM. A community-based walk-in centre was used to recruit MSM a...
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