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19
Vol. 57, No. 1, March 2012
Papers
Abstract
Introduction Many traditional preparations with varying
combinations of herbs have been used for over 1500
years to treat upper respiratory ailments, and reduce
their inciden c e and severity. Link Samahan ® is a
formulation containing the extract of 14 such medicinal
plants.
Objectives To test the efficacy of Link Samahan® in
reducing the incidence and severity of upper respiratory
symptoms in consenting healthy volunteers.
Setting MAS Linea Aqua, a factory with over 3000
employees, having its own health care centre with a
qualified matron and visiting medical officers.
Methods 956 healthy volunteers took daily either one
sachet of Link Samahan® in hot water (test group,
n=465, mean age 29.5 ± 7.7 years, women 418) or only
plain tea (control group n=491, mean age 29.7 ± 7.9,
women 448), for 84 consecutive days, and recorded
the incidence and severity of 15 upper respiratory
symptoms daily in a purpose-designed form.
Results At the end of 84 days, when compared to the
control group, the average incidence of symptoms in
the test group showed highly significant reductions at
p<0.001 for 6 symptoms and at p<0.005 for 3 symptoms,
and at p<0.05 for the remaining 6. Reduction of average
incidence over time also was highly sign ificant
(p<0.001) for 2 symptoms and (p<0.005) for 7, and
significant (p<0.05) for 4 symptoms, but only marginal
for the balance 2. Severity was significantly reduced
(p<0.05) for 7 symptoms, and reduced also for the other
8 according to descriptive analysis, though not
significant at the 5% level.
Conclusions The results indicate that Link Samahan®
taken as one sachet daily significantly reduces average
incidence, incidence over time, and severity of 15 upper
respiratory symptoms in healthy adults.
Ceylon Medical Journal 2012; 57: 19-32
The effect of a herbal formulation on the incidence and severity of
upper respiratory symptoms in healthy volunteers: an open-label,
randomised controlled clinical trial
C Goonaratna1, M R Sooriyarachchi2
(Index words: upper respiratory symptoms, short form WURSS-21, herbal medicinal product)
1Emeritus Professor of Physiology, University of Colombo and Registrar, Ceylon Medical College Council; 2Professor,
Department of Statistics, University of Colombo, Sri Lanka.
Correspondence: CG, e-mail: <si7np5e@gmail.com>. Received 30 November 2011 and revised version accepted
11 January 2012. Competing interests: CG is an Advisor on Clinical Research to Link Natural Products (Pvt) Ltd.
Introduction
Many herbal preparations have been used as
decoctions in the treatment and prevention of upper
respiratory tract ailments with catarrhal symptoms in
Ayurveda and in our island’s unique Desheeya Chikitsa
for over 15 centuries. The most widely used plants
include Adhatoda vasica, Alpinia galanga, Carum
copticum, Coriandrum sativum, Coscinium fenestratum,
Cuminum cyminum, Evolvulus alsinoides, Glycyrrhiza
glabra, Hedyotis corymbosa, Piper longum, Piper
nigrum, Premna herbacea, Solanum xanthocarpum, and
Zingiber officinale. Link Samahan® is an over-the-
counter standardised preparation made from these plants
in the proportions advised by a panel of senior and
clinically experienced Ayurveda physicians. The
concentrated oleoresin extract of the plants is wet
granulated, dried and formulated as water-soluble
aromatic granules marketed in triple-laminated sachets,
each containing 4 g. Link Samahan® (test herbal product)
may be taken dissolved in hot water, or in a beverage
such as tea or coffee.
The test herbal product has been widely used for
over 15 years, both in Sri Lanka and overseas. However,
its efficacy in reducing the incidence and severity of upper
respiratory symptoms has not been previously tested in a
clinical trial.
Methods
We designed an open-label, randomised, controlled
clinical trial to test its efficacy in healthy volunteers. The
assessors of efficacy (i.e. data entry operators and
statisticians) were blinded regarding the group (i.e. test or
control) to which participants belonged. A placebo could
not be used although the packeting technology was
readily available as the aroma of this herbal product is
instantly identifiable and cannot be masked or replicated
by a placebo. The healthy volunteers were selected from
employees of MAS Linea Aqua, a garment factory with
high ethical standards of worker welfare.
20 Ceylon Medical Journal
Papers
After initial meetings with the senior management
and human resource managers of the factory, several
meetings were held with groups of workers to explain the
objectives and procedural details of our study. From 1311
consenting volunteers 956 (465 and 491 in the test and
control groups respectively) were enrolled in the study.
The exclusion criteria were actual or suspected pregnancy,
lactation, significant systemic disease, and a history of
bronchial asthma. The inclusion criteria were age between
20 and 50 years, and willingness to give witnessed and
written informed consent to participate in the clinical trial
for 84 consecutive days.
At the study’s completion, a further 155 were
excluded from analysis (79 and 76 respectively from the
test and control groups) because they had not completed
the forms properly for varying periods, so only 801
participants (386 from the test and 415 from the control
group respectively) were included for data entry and
statistical analysis.
The evaluative instrument used in our study is the
short form Wisconsin Upper Respiratory Symptom Survey
(WURSS - 21), the performance of which has been
validated for reliability, responsiveness, importance-to-
patients and convergence with other measures [1,2]. Of
the 21 symptoms in WURSS - 21, we selected 15 as being
most appropriate for our cultural background by focus
group discussion and consultation with senior Ayurveda
physicians. The selected symptoms are given in Table 1.
The 15 selected symptoms were translated into
Sinhala (there were no Tamil participants) and back-
translated into English by language experts before
inclusion in the form that was to be filled by all participants
in both test and control groups daily (Figure 1). The forms
were colour-coded for enhanced clarity, and collected every
week from participants by members of the research team.
Allocation of participants to the test or control group
was randomised by each volunteer selecting from a box
containing identical sealed envelopes with a card inside
labelled “Test” or “Control”, opened in view of the
volunteer. The flow of participants through the study is
given in Figure 2.
A “cold day” was defined as one where an individual
had 7 or more of the symptoms listed [1,2]. From a pilot
study among factory workers the probability of a “cold
day” was estimated as 0.1949 for the control group. Setting
the significance level at 5%, the power of the study at
90%, and the reference improvement in the test group to
be 25% that of the control group, and employing a
recognised sample size calculation for a binary response
[3], 704 was the resultant total number for both groups of
participants. The number recruited was 1020, to compensate
for anticipated “last moment” decisions to refrain from
participation (63/1020, 6.2% in our study), and failure to
fill the forms properly (155/956,17.6%) (Figure 2).
The average incidence of symptoms in each group
was estimated as follows. Initially, for each participant the
percentage of days (out of the total of 84 days) with a
given symptom was determined. This was averaged over
all participants in each group. The significance of the
difference in incidence between the control group and the
test group was tested using a hypothesis test based on
the binominal approximation to the normal.
To compare the performance of each group over time
during the entire 12-week period of the study, the average
percentage of incident-free days for each week was
calculated for each symptom, from the responses of each
individual participant.
Figures 3 - 6 show descriptive trend lines for
incidence of 4 upper respiratory symptoms for the test
and control groups, where the vertical axis indicates the
percentage number of days participants did not have the
particular symptom during each week, through the entire
period of 12 weeks. Trend lines for all 15 symptoms are
similar to the four depicted here. All are approximately
linear, and in all 15 the trend line for the test group is
steeper than that for the control group, indicating that
there is an improvement over time of the particular
symptom’s incidence, in the former group. To confirm this,
a general linear model must be fitted to the data, but doing
so requires the assumption that the response variable,
namely, the average number of days without a given
symptom over time, follows a normal distribution for both
test and control groups, over 12 weeks [4].
Table 1. Symptoms selected from WURSS - 21
for our study
1. Excess sneezing
2. Watery nasal discharge
3. Nasal congestion
4. Itching of eyes and tearing
5. Scratchy throat
6. Throat pain
7. Hoarseness of voice
8. Feverishness
9. Cough
10. Tiredness
11. Headache
12. Itchy ears, blocked ears
13. Loss of appetite
14. Body pains
15. Difficulties in daily activities
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Vol. 57, No. 1, March 2012
Papers
The relevant general linear model [4] can be expressed
as: Yi = a + ti + gj + (t.g)ij + ei
Where, i = 1, to 12; j = 1, 2; a = overall mean; Yi =
average incidence over week i; ti = effect of ith week; gj =
effect of jth group; (t.g)ij = the combined effect of ith week
and jth treatment group; and ej = error term corresponding
to the ith observation.
To verify the requisite assumption normal probability
plots were composed for all 15 symptoms for both groups.
The four probability plots corresponding to the 4
symptoms in figures 3 - 6, are shown in figures 7 - 10. It is
clear from figures 7 - 10 that the average percentages of
symptom-free days for the 12 weeks, for both groups, are
approximately linear and fall well within the 95%
confidence limits. The pattern of all other probability plots
were similar to those shown as examples in figures 7 - 10,
over the entire study period of 12 weeks.
Since normal probability plots indicated that the
responses had an approximate normal distribution, and
descriptive trend lines showed that the trends were
approximately linear, the general linear model shown above
was fitted with the response variable being the average
incidence over the total number of participants in each
group, and the exploratory variables being the week (going
from 1 to 12), the treatment group (going from 1 to 2), and
their interaction [4]. The main focus of interest here was
the interaction between each week and group, and testing
whether there was a steeper trend over 12 weeks in the
test group when compared to the control group.
For assessment of severity of the symptoms the
response of each participant for each of the 15 symptoms
in both groups was coded as: 0 = no symptom, 1 = mild
symptom, 2 = moderate symptom, and 3 = severe symptom
(Figure 1). Differences in proportions between the control
and test groups were tested as in the comparison performed
for average incidence (see above), the only difference
being that in comparing severity, three proportions were
calculated (viz. mild versus no symptom, moderate versus
no symptoms, and severe versus no symptom).
Our study has been approved by the Sri Lanka
Medical Association’s Ethical Review Committee (ERC/
10-14), and registered by the Sri Lanka Clinical Trials
Registry (SLCTR/2011/001).
Figure 1. Colour-coded response form. This was translated into Sinhala for participants’ use.
22 Ceylon Medical Journal
Papers
Figure 2. Flow of participants through the study.
Excluded n=291.
Reasons: did not meet inclusion
criteria; had exclusion criteria;
declined participation
** Forms incompletely filled.
*Did not start participation; test group n=41, control group n=23
® - Randomisation
®
Assessed for eligibility
n=1311
n=1020
Data analysed
n=386
**Data excluded from
analysis n=79 (15.5%)
*Started participation
n=465
Link Samahan group
n= 506
Control group
n=514
*Started participation
n=491
Data analysed
n=415
** Data excluded from
analysis n=76 (17%)
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Vol. 57, No. 1, March 2012
Papers
Figure 3. Percentage of days with no excessive sneezing over time for the two groups.
Figure 7. Normal probability plot for excessive sneezing for the two groups.
24 Ceylon Medical Journal
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Figure 4. Percentage of days with no watery nasal discharge over time for the two groups.
Figure 8. Normal probability plot for watery nasal discharge for the two groups.
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Vol. 57, No. 1, March 2012
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Figure 5. Percentage of days with no nasal congestion over time for the two groups.
Figure 9. Normal probability plot for nasal congestion for the two groups.
26 Ceylon Medical Journal
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Figure 6. Percentage of days with no itching of the eyes and tearing over time for the two groups.
Figure 10. Normal probability plot for itching of eyes and tearing for the two groups.
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Vol. 57, No. 1, March 2012
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Figure 12. Gas liquid chromatography (GLC) fingerprint of Link Samahan®.
Time/Minute
Ditector response/pA
Column:DB-WAX capillary (30 m x 0.32mm, id 0.25) m film, Temperature programme: 35°C to 225°C, Detector: FID
Figure 11. High performance liquid chromatography (HPLC) fingerprint of Link Samahan®.
Time/Minute
Ditector response/AU
Column: Eclipse XDB -C18 (4.6 x 150 mm), Detector wavelength: 254 nm, Mobile phase: methanol/water, linear gradient.
28 Ceylon Medical Journal
Papers
Results
A total of 1020 healthy adult volunteers who initially
volunteered to participate in our clinical trial were
randomised to a test group (n=506) and a control group
(n=514) after obtaining informed consent. However, only
956 volunteers (test group n=465, control group n=491)
actually started participation. Visual scanning at the end
of the trial revealed that 79 participants from the test group
and 76 from the control group had not filled the forms
properly for varying periods, and had to be excluded from
final analysis, so only 386 from the test and 415 from the
control group were taken for data entry and statistical
analysis.
The mean ages of the test group (29.5 7.7 years)
and the control group (29.7 7.9 years) were closely similar.
The preponderance of women in both groups (test group
89.8%, control group 91.2%), is merely a reflection of their
extremely high proportion (approximately 90.2%) in the
entire workforce.
MAS Linea Aqua, a factory producing swimwear for
export, was selected for our trial for several relevant
reasons. It employs a committed, highly productivity-
oriented workforce of over 3000, its working environment
is tightly regulated for ambient temperature, relative
humidity and laminar airflow (thus minimising
environmental variables during working time of
participants), its high ethical standards regarding
workforce welfare, and convenience for monitoring herbal
test product intake daily and for collecting the purpose-
designed forms during a 84-day period of both groups.
The intake of the test herbal product by the
appropriate group of participants was supervised daily
by trained science graduates of our research team. They
also supervised gathering the relevant data collection
forms weekly from the participants. All participants were
allocated a distinctive number at the point of
randomisation, which was printed on the data collection
forms given to them. This number was known to and its
confidentiality was protected by, one science graduate
member of the research team, who played no further role
in the clinical trial except for separating the collected forms
to each group for the purpose of data entry.
At the study’s conclusion the average incidence of
upper respiratory symptoms, estimated as described above,
in the test group showed highly significant reductions at
p<0.0001 for 6 symptoms and at p<0.005 for 3 symptoms,
and a significant reduction (p<0.05) for the remaining 6
(Table 2), when compared to the control group.
Table 2. Comparison of average incidence
Symptom * Estimate for 95% confidence Z value P value
difference in interval for difference
incidence in incidence
(Control - Samahan) (Control - Samahan)
Excessive sneezing (1) 0.214227 (0.274952, 0.153502) 6.091 <0.001
Body pains (14) 0.152330 (0.219835, 0.0848262) 4.042 <0.001
Difficulties in daily activities (15) 0.120138 (0.183383,0.0568933) 3.72 <0.001
Headache (11) 0.118053 (0.184354,0.0517507) 3.49 <0.001
Tiredness (10) 0.113019 (0.178663,0.0473757) 3.37 <0.001
Nasal congestion (3) 0.106879 (0.169676,0.0440811) 3.34 <0.001
Watery nasal discharge (2) 0.0906735 (0.153244, 0.0281028) 2.84 0.005
Throat pains (6) 0.0843387 (0.142736, 0.0259386) 2.83 0.005
Itching of the throat (5) 0.0840087 (0.142594, 0.0254230) 2.81 0.005
Loss of appetite (13) 0.0808508 (0.141356,0.0203452) 2.62 0.009
Cough (9) 0.0804254 (0.143134,0.0177166) 2.51 0.012
Itching and blocking of the ears (12) 0.0749943 (0.133643,0.0163454) 2.51 0.012
Hoarseness of voice (7) 0.0684705 (0.124039,0.0129024) 2.42 0.016
Feverishness (8) 0.0597663 (0.109507,0.0100257) 2.36 0.019
Itching of the eyes and tearing (4) 0.0695622 (0.127650,0.0114749) 2.35 0.019
*The number in parentheses in the symptoms column corresponds to those shown in table 1.
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Vol. 57, No. 1, March 2012
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Table 3. Incidence over time
Symptom* Least squares Least squares P value
mean of % of mean of % of
symptom free symptom free
days over time days over time
(Control Group) (Samahan Group)
Itching of the eyes and tearing (4) 73.1 77.2 <0.0001
Headache (11) 54.5 61.9 <0.0001
Itching and blocking of the ears (12) 72.3 76.6 0.0003
Watery nasal discharge (2) 64.3 69.9 0.0004
Cough (9) 63.7 68.2 0.0004
Excessive sneezing (1) 67.0 70.5 0.0006
Nasal congestion (3) 61.8 69.4 0.0012
Tiredness (10) 56.5 63.4 0.0022
Itching of the throat (5) 69.1 75.5 0.0023
Hoarseness of voice (7) 75.9 80.7 0.0077
Feverishness (8) 83.7 88.3 0.0124
Loss of appetite (13) 68.6 74.7 0.0357
Throat pains (6) 70.1 77.5 0.0472
Difficulties in daily activities (15) 63.6 73.8 0.0517
Body pains (14) 48.6 61.0 0.0578
*The number in parentheses in the symptoms column corresponds to those shown in table 1.
Table 4. Comparison of average severity
Symptom Improvement Estimate of 95% confidence Z value P-Value
Category severity (vs no interval for
symptoms), difference in
Control - Samahan severity (Control -
Samahan)
Excessive sneezing Severe 0.477010 (0.532989, 16.70 <0.001
0.421031)
Nasal discharge NS NS NS NS NS
Nasal congestion NS NS NS NS NS
Itching and tearing eyes NS NS NS NS NS
Itching of the throat Mild 0.0539721 (0.106497, 2.00 0.046
0.00144698)
Throat pain Mild 0.541667 (0.106389, 2.02 0.044
0.00194428
(Continued)
30 Ceylon Medical Journal
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Table 5. Severity analysis
Symptom Severity result
Excessive sneezing Severe category improvement
Nasal discharge No improvement
Nasal congestion No improvement
Itching and tearing eyes No improvement
Itching of the throat Mild category improvement
Throat pains Mild category improvement
Hoaseness of voice Moderate category improvement
Fever No improvement
Cough No improvement
Tiredness No improvement
Headache Mild category improvement
Itching and blocking ears No improvement
Loss of appetite No improvement
Body pains Mild category improvement
Difficulties in daily activities Severe category improvement
Symptom Improvement Estimate of 95% confidence Z value P Value
Category severity (vs no interval for
symptoms), difference in
Control - Samahan severity (Control -
Samahan)
Hoaseness of voice Moderate 0.0433296 0.0821080, 2.16 0.030
0.00455109)
Fever NS NS NS NS NS
Cough NS NS NS NS NS
Tiredness NS NS NS NS NS
Headache NS NS NS NS NS
Itching and blocking ears NS NS NS NS NS
Loss of appetite NS NS NS NS NS
Body pains Mild 0.0690449 (0.130484, 2.19 0.029
0.00760612)
Difficulties in daily activities Severe 0.0519955 (0.0940458, 2.39 0.017
0.00994519)
NS – not significant
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Vol. 57, No. 1, March 2012
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The results of our model-based test [4] indicated that
except for 2 symptoms (viz. difficulties in daily activities
and body pains), the test herbal product showed a highly
significant reduction over time at p<0.0001 for 2 symptoms
and at p<0.005 for 7 symptoms, and a significant reduction
(<0.05) for 4 symptoms, during the entire study duration
(Table 3) in the test group when compared to the control
group.
Severity of symptoms as assessed by participants
on a scale of 0, 1, 2 and 3 (Figure 1), and estimated
statistically as detailed earlier, also showed a significant
reduction (p<0.05) for 7 symptoms, and a reduction of the
other 8 symptoms too on descriptive analysis, though the
latter were not significant at the 5% level (Tables 4 and 5),
when the test group was compared to the control group.
The high performance liquid chromatography and
gas liquid chromatography fingerprints of Link Samahan®,
which are just two of the battery of quality assurance
tests routinely performed during the manufacturing
process and of the finished product, are given in Figures
11 and 12.
Discussion
Our study compared the effect of taking one sachet
daily of a herbal product in hot water for 84 consecutive
days, on 15 upper respiratory symptoms, previously
validated for reliability, responsiveness, importance to
patients, and convergence with other measures, in a cohort
of healthy volunteers (test group, n=465), with a similar
cohort taking only plain tea at approximately the same
time of day (control group, n=491), both cohorts being
derived from a total of 1020 volunteers by random
allocation to each group [1,2].
The herbal product we have tested has been
registered by the Department of Ayurveda (Registration
number 02/01/PD/08/148). It has been in use extensively
locally as well as in foreign countries for over 15 years as
an over-the-counter convenient preparation for upper
respiratory tract ailments with catarrhal symptoms.
However, its putative efficacy in reducing the incidence
and severity of upper respiratory symptoms had not been
tested in a clinical trial before our study.
The test herbal product is an extract of 14 medicinal
herbs: Adhatoda vasica (root [5]), Alpinia galanga
(rhizome [6]), Carum copticum (seed [7]), Coriandrum
sativum (seed [8]), Coscinium fenestratum (stem [9]),
Cuminum cyminum (seed [10]), Evolvulus alsinoides
(whole plant [11]), Glycyrrhiza glabra (root [12]), Hedyotis
corymbosa (whole plant [13]), Piper longum (fruit [14]),
Piper nigrum (fruit [15]), Premna herbacea (root [16]),
Solanum xanthocarpum (whole plant [17]), and Zingiber
officinale (rhizome [18]).
From the large number of references available for the
efficacy and the probable pharmacologic basis for
beneficial effects of individual components, we have here
quoted only one for each. However, it needs to be
emphasized that we have performed an extensive literature
survey to exclude with confidence the possibility of
adverse effects of all 14 plants.
Seminal WHO recommendations for evaluation of
herbal medicinal products, while noting the importance of
robust research and encouraging clinical trials, has
observed that these medicines may be regarded as a rich
source of potentially useful therapies, and that actual
benefits remain to be identified by clinical trials conforming
to modern principles of clinical research [19]. The WHO
guidelines specifically state also that substantial prior
human use of traditional herbal substances or products
conveys reasonable confidence that they can be
administered safely in clinical trials, and that clinical
evaluation does not require purification of the herbal
medicinal products to single chemical constituents,
because the mixture of uncharacterised constituents
provides the postulated unique additive or synergistic
advantage of herbal medicines [19]. In a nutshell these
WHO recommendations comprise the justification for our
study.
The literature survey that we conducted indicated
that the plants used in the manufacture of the product we
have tested have anti-pyretic (eg. Premna herbacea,
Zingiber officinale), anti-inflammatory (eg. Hedyotis
corymbosa, Piper nigrum), anti-bacterial (eg. Alpinia
galanga, Coriandrum sativum), anti-viral (eg. Cuminum
cyminum), anti-allergic (eg. Glycyrrhiza glabra),
expectorant (eg. Solanum xanthocarpum, Evolvulus
alsinoides), anti-spasmodic (eg. Carum copticum,
Coscinium fenestratum), and anti-tussive (eg. Zingiber
officinale, Solanum xanthocarpum) activity that are likely
to relieve upper respiratory symptoms, commonly referred
to as catarrh, associated with viral, bacterial or allergic
upper respiratory inflammation [5 - 18, 20]. Of particular
interest were reports that several of these herbs (eg.
Adhatoda vasica, Piper longum, Piper nigrum, Zingiber
officinale) have immune-stimulatory actions, which are
likely to diminish the incidence of episodic upper
respiratory inflammation. Hence our study protocol was
designed to investigate average incidence, incidence over
time, and a severity assessment by participants, of
incidents of upper respiratory symptoms over 84
consecutive days while taking one sachet daily of the test
herbal product, compared to a similar group not taking the
test herbal product.
We have tried, as far as is practically possible, to
conform to the accepted principles of randomisation and
blinding [21]. In our clinical trial, the principal investigators,
trained data entry form collectors, trained data entry
operators, and consultant statisticians who performed the
analyses were blinded to the identity of the group to which
volunteer participants belonged, until after the results of
all statistical analyses were completed [22].
However, it was impossible to formulate a suitable
placebo for the test product because of its characteristic
aroma, as we have indicated above. As a consequence,
the control group participants took plain tea, instead of
the test product dissolved in hot water at about the same
32 Ceylon Medical Journal
Papers
time of day as the test group. Insuperable problems of
“blinding” in certain clinical trials has been discussed in
detail by experts in the field, but no statistically acceptable
solution is available for dissociating a possible placebo
effect in such trials as the present one [21, 22]. Since
participants in both test and control groups in our study
assessed severity of the 15 selected symptoms, awareness
of a possible “placebo effect” in the former assumes
importance in interpretation of the results.
Conclusions
In a substantial sample of 386 healthy adults working
in a highly productivity-oriented garment factory
producing swimwear for export who took one sachet of
the test herbal product in warm water daily, the results of
our study show a significant reduction in the average
incidence of all 15 upper respiratory symptoms selected
from a group of 21 symptoms previously validated in
community surveys, a significant reduction of 13
symptoms over time, and a significant reduction in
participant-assessed severity of 7 symptoms with a non-
significant reduction of the other 8, when compared to a
cohort of 415 who did not take the test herbal product
[1,2]. Taken together these results show the effectiveness
of the test herbal product, and its benefits in reducing
incidence, incidence over time and severity of the 15 upper
respiratory symptoms.
The results of our study warrant the extension of
clinical trials of this herbal product to patients who suffer
from conditions such as seasonal or perennial rhinitis and
conjunctivitis. Our results indicate yet another dimension
for investigation, i.e. the probable effects of the herbal
product in curbing absenteeism and increasing output
among employees in highly productivity-oriented
industries by reducing incidence and severity of
troublesome upper respiratory symptoms.
Acknowledgements
Link Natural Products (Pvt) Ltd provided funding for
the entire study. We thank the management of MAS Linea
Aqua for agreeing to provide access and optimum facilities
for our study, and all the employees of the factory who
cooperated cheerfully with us during the lengthy period
of our clinical trial.
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