Nijsten, T

Stern, RS

Unaeze, J

Elsevier - Publisher Connector 

A146 Abstracts
examine which drugs had generic equivalents available for each
year. The Pharmaceutical Red Book was referred for drug pricing
and product information. RESULTS: Generic drugs accounted
for almost half of total prescription drugs dispensed in 2003 as
compared to 19% in 1983. In 1990, two of the ten drugs pre-
scribed in outpatient clinics were generics, which rose to six in
2003. Out of ten top-selling drugs, six drugs will lose their
patents in next ﬁve years. In 1990, none of the top ten derma-
tological drugs were generics. With few drugs losing their patents
since 1990 (e.g. Retin-A®), two out of top ten dermatological
drugs were generics in 2003. CONCLUSIONS: This study ﬁnds
an increasing trend in the availability of generic medications.
However, concerns regarding the bioavailability of generic equiv-
alents used in dermatological conditions may limit their use.
However, increased pressure from managed care organizations
to prescribe inexpensive generics, overall growth in generic drug
market, and anticipated drug patent expirations may inﬂuence
prescribing patterns of these medications.
PSN11
PREDICTORS OF HEALTH CARE OUTCOMES AND COSTS
RELATED TO MEDICATION USE IN PATIENTS WITH ACNE IN
THE UNITED STATES
Balkrishnan R1, Kulkarni A1, Feldman S2
1Ohio State University College of Pharmacy, Columbus, OH, USA;
2Wake Forest University School of Medicine, Winston Salem, NC,
USA
OBJECTIVE: To investigate the relationship between health
status, costs linked with the treatment of acne in the United
States and aspects related to medication use. METHODS: The
United States Medical Expenditure Panel Survey (MEPS) data-
base was analyzed for a cohort of people with acne. Patients for
this study were identiﬁed using the ICD-9 (International Classi-
ﬁcation of Diseases, 9th revision) code “706” for acne vulgaris
and similar conditions (The MEPS dataset uses only the ﬁrst
three digits of the ICD-9 codes to identify disease states). Records
of medical events were obtained using this ICD-9 code for acne
and the receipt of medication for acne. This cross sectional study
obtained costs, demographics, health care service utilization and
clinical patient variables from the MEPS database. The subjects
were divided into categories depending on type of medications
used, mainly, oral antibiotics, oral retinoids, oral contraceptives,
topical antibiotics, topical retinoids and oral contraceptives. The
EuroQOL (EQ-5D) scores available in MEPS for subjects 18
years and older were used for obtaining health status informa-
tion for these patients. Indices for medication adherence and
comorbidities were also calculated using the data from the
MEPS. Multivariate weighted analysis was performed on data
for approximately 5 million patients (weighted sample size).
RESULTS: Nearly 70% of the patients used some type of med-
ication for acne. Acne-related medication accounted for approx-
imately 36% of the total acne related health care costs, with an
average of 2 annual acne prescription reﬁlls. Increased number
of reﬁlls of acne speciﬁc drugs was associated with an improve-
ment in health status (p < 0.05). Increased ofﬁce based visits were
the only predictors of higher acne related health care costs (p <
0.01). CONCLUSIONS: Adherence to acne medications is an
important component of better health status. Pharmacological
treatment of acne does not signiﬁcantly add to acne-related
health care costs.
PSN12
NAIL PSORIASIS: ELABORATION OF A SCALE FOR
FUNCTIONAL DISCOMFORT
Taieb C1, Corvest M2,Voisard J3, Marionneau N1, Myon E1
1Pierre Fabre, Boulogne-Billancourt, France; 2APLCP,Vannes, France;
3Pierre Fabre Dermatologie, Lavaur, France
OBJECTIVES: To validate a scale for functional discomfort due
to nail psoriasis. The questionnaire will have to be adapted both
in the case of toe or ﬁnger nail psoriasis. The measured criterion
will be unidimensional and related to the bother caused by nail
psoriasis in daily life. METHODS: The scale was developed
according to the international recommendations on quality of
life. In October 2004, a questionnaire was sent to 4000
members, selected by drawing lots, among the French patients
support group (APLCP). The ﬁrst step of the process has led to
the selection of 10 items related to functional discomfort induced
by nail psoriasis. RESULTS: In total, 795 questionnaires con-
cerning individuals affected by nail psoriasis were analysed. Val-
idation analyses included the 10 selected items. Questionnaire’s
contents were coherent with the a-Cronbach coefﬁcient equaling
0.88. The unidimensional feature of the questionnaire was veri-
ﬁed: the analysis in principal components revealed that 49% of
the total variance was explained by one component. The DLQI
speciﬁc to dermatological pathologies was also given and
enabled a comparison with the scale. Pearson’s correlation coef-
ﬁcient between both scales was 0.48. The severity of the affec-
tion assessed through the DLQI evolved in the same way as the
evaluation for the “Nail Psoriasis” scale. A test-retest performed
on a sample of 15 individuals showed that the scale could be
reproduced with an intra-class correlation coefﬁcient of 0.82
between 2 administrations. CONCLUSION: The “Nail Psoria-
sis” scale is simple to use and easy to give to the patient. The
qualitative features which must be found in a quality of life scale
have been checked: comprehensibility, reliability and validity.
The scale will have to be used during clinical trials in order to
demonstrate its ability in measuring change in condition (before
and after treatment).
PSN13
REFINEMENT AND REDUCTION OF THE IMPACT OF
PSORIASIS QUESTIONNAIRE: CLASSICAL TEST THEORY VS
RASCH ANALYSIS
Nijsten T1, Unaeze J2, Stern RS3
1University Hospital of Antwerp, Edegem, Belgium; 2Harvard medical
school, Boston, MA, USA; 3Beth Israel Deaconess Medical Center,
Harvard Medical school, Boston, MA, USA
Quality of life instruments are increasingly important in assess-
ing disease severity. However, some of these measurements have
been developed on a more or less ad hoc basis. Although not
well standardised, psychometric analyses can be used to re-test,
reﬁne and shorten existing quality of life instruments more
strictly. OBJECTIVES: To psychometrically test and reﬁne the
Impact of Psoriasis Questionnaire (IPSO) and to compare the
results of two different statistical approaches. METHODS:
Among 792 psoriasis patients who were included in the PUVA
Follow Up Study, we used Classical Test Theory (CTT) and
Rasch analysis to test and optimise the IPSO. Thereafter, two
shortened versions of the IPSO derived from these models were
compared. RESULTS: CTT analyses of the original IPSO demon-
strated suboptimal item performance for 6 of 16 items and inap-
propriate subscaling. In contrast to the original 4 subscales,
factor analysis of the CTT version yielded 3 subscales (mental
functioning, mental wellbeing and stigmatisation). The Rasch
approach, which included ordering of thresholds, differential
item functioning and item ﬁt, resulted in an unidimensional 11-
A147Abstracts
item questionnaire. Although the two new versions of the IPSO
shared only 6 items, both reﬂected the original IPSO well.
However, several arguments such as lower correlation coefﬁ-
cients, higher Chronbach’s alpha’s, ordered thresholds, unidi-
mensionality and less differences among subgroups of patients
suggested that the Rasch version of the IPSO may be the pre-
ferred instrument to use. CONCLUSION: The IPSO can be
improved and shortened and the Rash reduced version of this
instrument is likely to assess the psychosocial impact of moder-
ate to severe psoriasis on patients’ lives best because it is a short,
reliable and unidimensional measurement.
PSN14
CHANGES IN FUNCTIONAL ABILITY AS MEASURED BY DLQI
IS CONSISTENT WITH CLINICAL RESPONSE IN MODERATE
TO SEVERE PLAQUE PSORIASIS PATIENTS TREATED WITH
ADALIMUMAB
Melilli LE1, Shikiar R2,Thompson C3
1Abbott Laboratories, Abbott Park, IL, USA; 2MEDTAP Institute at
United Biosource Corporation, Seattle, WA, USA; 3MEDTAP Institute
at United Biosource Corporation, Bethesda, MD, USA
OBJECTIVES: Because of physical limitations associated with
psoriasis, dermatologic-related functional ability can be an
important endpoint to assess effectiveness of treatment. This
study was performed to assess the correlation between clinical
efﬁcacy and improvement in functional ability in moderate to
severe plaque psoriasis patients treated with adalimumab for 12
weeks. METHODS: In a randomized, double-blind, placebo-
controlled, multi-center clinical trial for the treatment of mod-
erate to severe plaque psoriasis with adalimumab, the correlation
between clinical efﬁcacy and change in dermatology-speciﬁc
functional limitations was evaluated. Clinical efﬁcacy was
assessed using the Psoriasis Area and Severity Index (PASI) and
the Physician’s Global Assessment (PGA) of Disease Severity. The
Dermatology Life Quality Index (DLQI) was used to measure
dermatologic-speciﬁc functional limitations. Mean changes in
DLQI scores were evaluated for patient responses between base-
line and 12 weeks. RESULTS: The DLQI was shown to have
good reliability, and to demonstrate responsiveness to change
with the subjects’ PASI and PGA scores from baseline to week
12. The correlation between DLQI and PASI response was 0.69
(p < 0.001), and between DLQI and PGA response was 0.71 (p
< 0.001). Mean change in DLQI was +12.17 points in patients
who achieved signiﬁcant clinical beneﬁt (> = PASI 75 response)
vs. +1.77 points in nonresponders (less than PASI 50 response).
CONCLUSIONS: DLQI was demonstrated to be highly respon-
sive to clinical changes in patients with moderate to severe
plaque psoriasis. The level of agreement suggests that adali-
mumab may be highly effective in improving both the physical
disease manifestations and functional ability of patients with
moderate to severe plaque psoriasis.
PSN15
QUALITY OF LIFE IMPROVEMENT AS MEASURED BY EQ-5D IS
CONSISTENT WITH CLINICAL RESPONSE IN MODERATE TO
SEVERE PLAQUE PSORIASIS PATIENTS TREATED WITH
ADALIMUMAB
Melilli LE1, Shikiar R2,Thompson C3
1Abbott Laboratories, Abbott Park, IL, USA; 2MEDTAP Institute at
United Biosource Corporation, Seattle, WA, USA; 3MEDTAP Institute
at United Biosource Corporation, Bethesda, MD, USA
OBJECTIVES: Because moderate to severe psoriasis can nega-
tively impact patients’ daily living, quality of life can be an
important parameter to assess in determining effectiveness of
treatment. This study was performed to assess the correlation
between clinical efﬁcacy and quality-of-life improvement in mod-
erate to severe plaque psoriasis patients treated with adalimumab
for 12 weeks. METHODS: In a randomized, double-blind,
placebo-controlled, multi-center clinical trial for the treatment of
moderate to severe plaque psoriasis with adalimumab, the cor-
relation between clinical efﬁcacy and quality of life was evalu-
ated. Clinical efﬁcacy was assessed using the Psoriasis Area and
Severity Index (PASI) and the Physician Global Assessment
(PGA) of disease severity. Euro-QOL 5D (EQ-5D) visual ana-
logue score was used to assess general quality of life. Mean
changes in EQ-5D scores were evaluated for patient responses
between baseline and 12 weeks. RESULTS: EQ-5D demon-
strated responsiveness to changes in clinical efﬁcacy. The corre-
lation between EQ-5D and PASI response was 0.57 (p < 0.001),
and between EQ-5D and PGA response was 0.44 (p < 0.001).
Mean change in EQ-5D was 15.69 points in patients who had
achieved signiﬁcant clinical beneﬁt (>PASI 75 response) vs. 1.92
points in non-responders (<PASI 50 response). CONCLUSION:
EQ-5D was demonstrated to be responsive to clinical changes in
patients with moderate to severe plaque psoriasis. The level of
agreement suggests that adalimumab may be highly effective in
improving both the physical disease manifestations and quality
of life of patients with moderate to severe plaque psoriasis.
PSN16
NAIL PSORIASIS: IMPACT ON QUALITY OF LIFE
Taieb C1, Corvest M2,Voisard J3, Marionneau N1, Myon E1
1Pierre Fabre, Boulogne-Billancourt, France; 2APLCP,Vannes, France;
3Pierre Fabre Dermatologie, Lavaur, France
OBJECTIVES: The aim was to evaluate the consequences of pso-
riasis on quality of life and pay particular attention to those with
nail psoriasis. METHODS: In October 2004, a questionnaire
was sent to 4000 members, selected by drawing lots, among the
French patients support group (APLCP). The ﬁrst part concerned
the social and demographic characteristics of the patients, pso-
riasis localization and psoriasis age. The second part was dedi-
cated to patients with nail psoriasis. The last part was the
Dermatology Life Quality Index (DLQI) which was ﬁlled in by
all patients. RESULTS: A total of 1309 questionnaires were
returned with 57.3% of women and 42.7% of men. Mean age
was 51.8 years (SD = 16.2). Psoriasis affected the nails for 60.8%
of subjects (16.4% for the hands only, 9.4% for the feet only
and 35% for both the hands and feet). The DLQI score was
available for 1111 individuals with an average score of 8.3 (SD
= 6.5). It was signiﬁcantly related to gender with a score of 7.6
(SD = 6.2) for men and 9 (SD = 6.8) for women (p = 0.0333). It
was also signiﬁcantly related to age, the younger the individuals,
the more quality of life was affected: 9.4 (SD = 6.6) for the group
“39 years old and under”, 9.2 (SD = 6.7) for the group “40–54
years”, 7.8 (SD = 6.6) for the group “55–64 years” and 6.7 (SD
= 5.6) for the group “65 years old and above” (p < 0.0001).
Quality of life was also linked to the localization of the psoria-
sis. CONCLUSIONS: Quality of life assessed through the DLQI
shows an important impairment in the study population with a
mean score of 8.3. In comparison with other studies using the
DLQI; a score of 8.9 was found for severe psoriasis, 12.5 for
atopic dermatitis and 4.3 for acne.
PSN17
VALIDATION OF THE ITALIAN VERSION OF THE INFANTS’
DERMATITIS QUALITY OF LIFE & FAMILY DERMATITIS
INDEXES
Baranzoni N1, Scalone L2, Rigoni L3, Mantovani LG2, Giannetti A1
1Divisione Clinica Dermatologica, Modena, Italy; 2Center of
Pharmacoeconomics, University of Milan, Milan, Italy; 3Fujisawa Srl,
Milan, Italy


PSN13 REFINEMENT AND REDUCTION OF THE IMPACT OF PSORIASIS QUESTIONNAIRE: CLASSICAL TEST THEORY VS RASCH ANALYSIS 

Nijsten, Tamar

Unaeze, J.

Stern, R.S.

Institutional Repository Universiteit Antwerpen

Refinement and reduction of the impact of psoriasis questionnaire: classical test theory vs. Rasch analysis

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PSN13 REFINEMENT AND REDUCTION OF THE IMPACT OF PSORIASIS QUESTIONNAIRE: CLASSICAL TEST THEORY VS RASCH ANALYSIS

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