A Randomized Double-Blind Study of the Effect
of Distant Healing in a Population With Advanced AIDS Report of
a Small Scale Study
FRED SICHER, MA, ELISABETH TARG, MD; DAN MOORE 11, Ph.D.; and HELENE
S. SMITH, Ph.D.; San Francisco, California
A recent called for "the scientific community to stop giving
alternative medicine a free tide" (Angell M, Kassirer JP. Alternative
medicine: the risks of untested and unregulated remedies. N Engl
J Med 1998; 339:841). We agree. Now is the time for scientists to
be courageous, as well as careful and precise, to help separate
truth from hope and fact from myth. The paper published below is
meant to advance science and debate. It has been reviewed, revised,
and re-reviewed by nationally known experts in biostatistics and
in complementary medicine. It reports a 6-month blinded study of
40 patients with AIDS who knew they might receive distant healing
treatments representing variety traditions. Patients who received
treatment had a statistically significant more benign course than
control subjects. Does the paper prove that prayer works? No. The
authors call for more research, as do we and the reviewers, for
a number of reasons. We note that the study was relatively short
and analyzed rather few patients. No treatment-related mechanisms
for the effects were posited. The statistical methods can be criticized.
We have chosen to publish this provocative paper to stimulate other
studies of distant healing and other complementary practices and
agents. It is time for more light, less dark, less heat.
-Linda Hawes Clever, MD
Editor
Various forms of distant healing (DH), including prayer and "psychic
healing,' are widely practiced, but insufficient formal research
has been done to indicate whether such efforts actually affect health.
We report on a double-blind randomized trial of DH in 40 patients
with advanced AIDS. Subjects were pair-matched for age, CD4+ count,
and number of AIDS-defining illnesses and randomly selected to either
10 weeks of DH treatment or a control group. DH treatment was performed
by self-identified healers representing many different healing and
spiritual traditions. Healers were located throughout the United
States during the study, and subjects and healers never met Subjects
were assessed by psychometric testing and blood draw at enrollment
and followed for 6 months. At 6 months, a blind medical chart review
found that treatment subjects acquired significantly fewer new AIDS-defining
illnesses (0.1 versus 0.6 per patient, P = 0.04), had lower illness
severity (severity score 0.8 versus 2.65, P = 0.03), and required
significantly fewer doctor visits (9.2 versus 13.0, P = 0.01), fewer
hospitalizations (0. 1 5 versus 0.6, P = 0.04), and fewer days of
hospitalization (0.5 versus 3.4, P = 0.04). Treated subjects also
showed significantly improved mood compared with controls (Profile
of Mood States score -26 versus 14, P = 0.02). There were no significant
differences in CD4+ counts. These data support the possibility of
a DH effect in AIDS and suggest the value of further research.
(Sicher F, Targ E, Moore D, Smith HS. A randomized double-blind
study of the effect of distant healing in a population with advanced
AIDS --- report of a small scale study. West J Med 1 998; 1 69:356-363)
From the Geraldine Brush Cancer Research Institute (Mr Sicher and
Drs Targ, Moore, and Smith), California Pacific Medical Center,
Sausalito Consciousness Research Laboratory (Mr Sicher); and Departments
of Psychiatry (Dr Targ), Statistics (Dr Moore), and Medicine (Dr
Smith), University of California, San Francisco, California. Reprint
requests to Elisabeth Targ, MD, California Pacific Medical Center,
2300 California St, Suite 204, San Francisco, CA 94115. E-mail:
etarg@cooper.cpmc.org This work was supported in part by grants
from the Sausolito Consciousness Research Laboratory, the Institute
of Noetic Sciences, arid the Parapsychology Foundation.
ABBREVIATIONS USED IN TEXT
ADD = AIDS-defining disease
BHS = Boston Health Study
DH = distant healing
MOS = Medical Outcomes Survey for HIV
POMS = Profile of Mood States
WPSI = Wahler Physical Symptom Inventory
Distant healing (DH) is defined as a conscious, dedicated act of
mentation attempting to benefit another person's physical or emotional
well-being at a distance. Various forms of DH, including prayer
and some forms of spiritual healing, are widely reported and subscribed
to in the United States.1.2 Anecdotal experience with DH has stimulated
a substantial body of research including at least 131 laboratory-published
studies reviewed by Benor,3 of which 56 found significant effects.
Many of the studies, however, lacked rigorous control, measured
only responses in vitro, involved only brief periods of influence,
or did not include extended follow-up. The medical literature does
contain airport of a rigorously controlled clinical study by Byrd,4
who investigated the effects of intercessory prayer for 383 patients
sequentially admitted to the San Francisco General Hospital Coronary
Care unit. The study reported a significant improvement in hospital
course and decreased medical complications in the treated group,
but the period of medical follow-up was limited to the time each
subject spent in the hospital, so delayed effects were not studied.
In addition, outcome measures were not predefined. Thus, the longer-term
efficacy of DH remains unstudied, and additional, scientifically
rigorous studies are required to establish whether DH can be an
effective intervention for life-threatening disease.
TOP OF PAGE
For these reasons, and without having conducted any previous DH
studies at all, we chose to evaluate DH in a population of advanced
AIDS patients with 6-month follow-up. Our initial study was a double-blind
pilot study of 10 treated and 10 control subjects conducted during
July 1995 through January 1996. The pilot study suggested both medical
and psychological benefits of distant healing. Four of the 10 control
group subjects died, with no deaths occurring in the treatment group,
but the result was confounded by age (those who died were older).
As a result, in the second larger study (reported here in full)
a pairmatched design was used to control for factors shown to be
associated with poorer prognosis in AIDS,5 specifically age, T cell
count, and illness history. Additionally, an important intervening
medical factor changed the endpoint in the study design. The pilot
study was conducted before the introduction of "triple-drug
therapy" (simultaneous use of a protease inhibitor and at least
two antiretroviral drugs), which has been shown to have a significant
effect on mortality.' For the replication study (July 1996 through
January 1997, shortly after widespread introduction of triple-drug
therapy in San Francisco), differences in mortality were not expected
and different endpoints were used in the study design. Based on
results from the pilot study, we hypothesized that the DH treatment
would be associated with 1) improved disease progression (fewer
and less severe AIDS-defining diseases [ADDs] and improved CD4+
level), 2) decreased medical utilization, and 3) improved psychological
well-being. The results of this replication study are reported below.
Subjects and Methods
Forty subjects were recruited by distributing fliers at clinics
and at AIDS-related events and through advertisements in both gay
and mainstream newspapers in the San Francisco Bay Area. Efforts
were made to reach a wide range of socio-demographic populations.
All subjects were required to meet the criteria of the Centers for
Disease Control AIDS category C-3 (CD4+ cell count <200 cells/µ1,
history of at least one ADD)' and to be taking Pneumocystis carinii
pneumonia prophylaxis. Subjects signed informed consent, were photographed,
and were randomly assigned on a double-blind basis to either DH
or a control group. Subjects were told they had a 50-50 chance of
receiving the DH treatment. Both groups continued to receive standard
medical care at their primary care sites. Subjects were pair-matched
by age, CD4+ count, and number of ADDs' - before randomization.
Data acquisition
Subjects came to the laboratory or were visited at home to complete
baseline and repeated measures at enrollment, at the end of the
10-week treatment intervention, and at follow-up 12-14 weeks later
(Fig. 1). Measurements taken were CD4+ count, psychological distress
as measured by the Profile of Mood States (POMS),8 physical symptoms
as measured by the Wahler Physical Symptom Inventory (WPSI),9 and
quality of life as measured by the Medical Outcomes Survey (MOS)
for HIV,10.In addition, subjects reported doctor visits, hospitalizations,
illness recovery, and onset of new illnesses. To verify the report,
6 months from the start of the study a blind medical chart review
was performed by a study physician who catalogued outpatient doctor
visits, hospitalizations, and remission or development of ADDs over
the study interval. The review was done at 6 months only because
of the focus of the study on extended treatment effects. Additional
variables included subject's belief in the efficacy of DH, years
HIV-positive, previous ADDs, protease inhibitor use, triple-drug
therapy use, site of medical care delivery, use of complementary
health practices, social support for study participation, drug and
alcohol use, and demographics. Subjects were also asked, in a self-administered
questionnaire, which group they thought they were in, treatment
or control. For the one subject who died near the end of the study,
all data were collected except the final CD4+ count.
Evaluation of illness severity
To control for the variation in severity and prognosis of different
AIDS-related illnesses, all illnesses were scored according to the
Boston Health Study (BHS) Opportunistic Disease Score," which
includes both AIDS-defining and secondary AIDS-related diseases.
The BHS severity scoring system has been validated in predicting
survival in two large populations of AIDS patients. New ADDs were
counted as "ADDs acquired" only if blind chart review
revealed no prior diagnosis of the condition; the only exception
to this rule was Kaposi's sarcoma. Because cutaneous Kaposi's sarcoma
is scored in a different severity category than visceral Kaposi's
sarcoma, patients progressing from cutaneous to visceral Kapok's
sarcoma were counted as having acquired a new illness. Relapsing
and remitting opportunistic diseases such as thrush or herpes or
non-AIDS-defining bacterial infections were counted only once, whether
or not there were recurrences. Recoveries from ADDs were tabulated
when subjects' medical charts specifically stated a recovery had
occurred or that there had been no evidence of the illness for at
least 3 months.
Pair matching
Pair matching was done to control as much as possible for variation
in outcomes that might be related to major disease progression and
survival predictors, as indicated by the pilot study and in the
medical litemture.6.11. The variables were age, baseline CD3+ (T
cell) count, and history of ADDs (sum of previous and current ADDs).
These three variables were used to form matched subject pairs. First,
a normalized z score was computed for each subject for each variable
by subtracting the mean for all subjects and dividing the result
by the standard deviation for all subjects. Next, all pairwise sums-of-squared
differences in z scores between subjects (over the three variables)
were computed. For each subject, an average difference from all
the other subjects was calculated. Starting with the subject with
the largest average difference, the closest match was found. The
two matched subjects were eliminated from the list and the procedure
was iterated until all 40 subjects were paired. A computer-generated
binary random number was then used to randomly assign one member
of each pair to treatment and one to control.
Blinding procedures
All subject enrollment interviews were performed by one of two staff
members who assigned subjects enrollment numbers. After enrollment
was complete, a third staff member used a random number table to
assign "study code" numbers to each of the enrollment
numbers; these were substituted in the computer and used in randomization.
Medical charts were obtained at the end of the study; names were
removed from all text, and charts were assigned a new set of code
numbers before they were reviewed. The chart reviewer did not know
which subjects were in which group at the time of review. All data
were entered into the computer by a research assistant who was blind
to group assignment. Subjects learned their group assignment I year
after the study ended.
Treatment procedures
At the mm of enrollment all subjects were photographed, and subject
information packets including 5 x 7-inch color photograph, first
name, CD4+ count, and current symptoms were prepared by a research
assistant. Ten copies of each packet were made and marked with removable
labels indicating the subject's enrollment number. After randomization,
the enrollment numbers were removed from the packets and replaced
with the study codes. The packets were then divided into treatment
and control groups based on the randomization results. Control subject
packets were retained unopened in a locked file drawer. Treatment
subject packets were grouped in batches of five to be sent to each
healer. Each of the five envelopes sent to the healers was marked
with the day to be opened to begin the healing period for that patient.
Healers
Forty DH practitioners, including 12 from the pilot study, were
recruited via professional healing associations and schools of healing.
Eligibility criteria were minimum 5 years regular ongoing healing
practice, previous healing experience at a distance with at least
10 patients, and previous healing experience with AIDS.
Healers had an average of 17 years of experience and had previously
treated an average of 106 patients at a distance. Practitioners
included healers from Christian, Jewish, Buddhist, Native American,
and shamanic traditions as well as graduates of secular schools
of bioenergetic and meditative healing. Practitioners were not paid
and understood that the study could not evaluate the abilities of
any individual practitioner. Healers were residing at various locations
throughout the United States. The site from which they performed
their healing was not restricted.
Healing treatment
A rotating healing schedule randomized healers to subjects on a
weekly basis to minimize possible differences in healer effectiveness.
Thus, each subject in the DH group was treated by a total of 10
different practitioners, while each practitioner worked every other
week treating a total of 5 subjects. Each healer received five consecutively
numbered subject information packets with instructions specifying
the day to begin treatment on each subject. Healers were asked to
work on the assigned subject for approximately I hour per day for
6 consecutive days with the instruction to "direct an intention
for health and well-being" to the subject. Healers completed
logs for each healing session, indicating period of healing, specific
technique, and any impressions of the subject's illness. Subjects
never met practitioners and did not know whether they were in the
DH group, where the practitioners were located, nor at what time
the DH might occur. Before the intervention, study personnel encouraged
and motivated healers via letters and phone calls stressing the
importance of the study and their individual efforts.
Statistical methods
Baseline and outcome comparisons between the two groups involved
three statistical tests: paired t test for all continuous or multilevel
variables, Wilcoxon signed-rank test when the data appeared to be
skewed or contained outliners, and McNemar's test for 2 x 2 tables
comparing paired binary variables. For study outcomes where P <
0.05, since many of the outcomes had skewed or clumped distributions
(caused by tied values in outcome), a randomization test" was
also used to obtain an "exact" P value for the observed
outcome.
In addition, because study outcomes may be correlated, Hotelling's
T-square statistic was used to determine whether there was treatment
effect on the array of 11 medical and psychological outcomes. Again,
since this statistic assumes multivariate normality of the outcomes
(which is not the case), statistical significance of the outcome
array was further assessed by conducting a randomization test on
the T-square statistic. A randomization test is based on comparing
a set of observed outcomes with those generated by randomly permuting
the treatment-control, assignment of subjects. Randomization tests
are distribution free, that is, no assumption concerning the distribution
of the test statistic is required. In this way, an unbiased determination
of significance is obtained without assumptions concerning the distribution
of the test statistic. (An informative discussion of randomization
tests in a medical setting is contained in a recent issue of The
American Statistician.13) This method for determining statistical
significance was necessitated by the nature of the outcomes data.
We also examined the effects of differences in baseline factors
(those with two-sided p < 0.2) on outcome variables by stratifying
on levels of baseline factor when they were discrete and by analysis
of covariance when they were continuous.
Results
Baseline comparisons
Subjects were 37 men and 3 women with a mean age of 43 (Table 1).
Only one patient (DH group) had a history of intravenous drug use.
'Mere were no statistically significant differences on any baseline
measures between the treated and control groups, including those
used for pair-matching, or in ongoing AIDS management-related variables,
such as use of triple-drug therapy (Table 1). There were several
near-significant differences (P < 0.20), however. AU five baseline
smokers and all four minorities were in the control group (P = 0.06
and P = 0. 12, respectively). Of note, two treated subjects resumed
their smoking habit during the study period (one near the beginning
and one near the middle), reducing group smoking differences. The
control group also was HIV-positive for a shorter time (7.3 versus
9.0 years, P = 0. II), showed a trend toward lower initial psychological
distress scores (POMS 43 versus 62, P = 0. 19), and had used fewer
alternative therapies (2.7 versus 4.2, P = 0. I0). A review of primary
care sites found no significant differences in site or type of medical
practice (university, specialty clinic, solo practice). Review of
charts, each containing complete medical history, found no major
comorbid conditions (heart disease, cancer, diabetes) in either
group. A majority of subjects (85%) expressed an a priori belief
in the benefit of DH. The level of belief at baseline was nearly
equal for both groups, and the belief showed no con-elation with
medical outcomes.
Medical and psychosocial outcomes
Over the 6-month study period, the DH group experienced significantly
fewer outpatient doctor visits, fewer hospitalizations, fewer days
of hospitalization, fewer new ADDs, and a significantly lower illness
severity level as defined by the BHS scale (Table 2). AU diseases
acquired are fisted in Table 3. At 6 months, the DH group also showed
significantly improved mood compared with controls as measured by
the POMS, reflecting improvement on four of six subscales (depression,
P < 0.02; tension, P < 0.02; confusion; P < 0.002; fatigue,
P < 0.02). Differences on the WPSI and MOS were not significant
between groups. One death occurred in the control group, after the
patient's follow-up questionnaire had
been completed but I week before the 6-month study endpoint. There
was a nonsignificant trend toward increase in CD4+ count for both
groups, although the two groups did not differ significantly on
this measure. Thus, the DH treatment was associated with significantly
better outcomes on 6 of the 11 medical outcome measures.
At study midpoint, immediately after the treatment intervention,
subjects were asked if they thought they had been in the DH or control
group. Two subjects (one from each group) did not respond. Nine
of the DH group subjects and 13 of the control group subjects believed
they were in the DH group (P = 0.32; Fisher's exact test). Additional
analysis was done to investigate possible correlation between subject
belief about group assignment and study outcomes. Belief about group
assignment did not correlate with any study outcome except CD4+
change (P = 0.05). This correlation no longer held when subjects
were again asked to guess group assignment at the end of the 6-month
study period (P = 0.28). At the end of the study period, subjects
who had experienced more recoveries did tend to correctly guess
they had been in the treatment group (P = 0.05).
TOP OF PAGE
Baseline effects on outcomes
Where baseline group differences were near-significant (P < 0.20),
these variables were examined for correlation with all study outcomes.
We found no effects of the baseline differences in smoking, number
of years HTV-positive, or number of alternative therapies used on
any outcomes. As described above, the treatment group tended to
have higher baseline POMS scores (more distress) than controls.
Higher baseline psychological distress, in both groups, was significantly
correlated with greater reduction in psychological distress at the
end of the study (P < 0.001). When baseline POMS was used as
a covariate to adjust the POMS change scores, the difference in
POMS change scores switched from statistical significance in favor
of the treated to significance in favor of the controls. Baseline
POMS values did not significantly correlate with any of the medical
outcomes, although, as expected, they did correlate with the other
psychological measures.
Minority status (with all 4 minorities in the control group) showed
a near-significant difference at baseline. When this variable was
examined within the control group (4 minorities versus 16 nonminorities),
no significant correlation with study outcomes was found. However,
a stratified analysis on all subjects, which takes minority differences
in treatment-control pairs into account, resulted in a change in
the P values from 0.04 to 0.09 for number of hospital stays and
from 0.04 to 0.08 for number of hospital days. The difference in
minority status among treated and control did not significantly
correlate with any other outcome variable.
Analysis of Outcome Array
Many of the outcomes in Table 2 are correlated with each other.
Thus, it is useful to evaluate the treatment effect by using a statistic
that takes into account these correlations. The results of the randomization
test applied to Hotelling's T-square statistic indicated that the
array of all outcomes is statistically significant (P = 0.0154;
that is, in the 10,000 random samplings only 154 T-squares exceeded
the observed Hotelling T-square statistic).
Discussion
The findings of decreased medical utilization, fewer and less severe
new illnesses, and improved mood for the treated group compared
with the controls supports a positive therapeutic effect of DH.
This outcome is difficult to explain, particularly in this double-blind
study where subjects, physicians, and study personnel did not know
who was in the treatment group. There are two explanations other
than a DH effect that, in principle, could explain these data.
First, differences between the group outcomes might be attributed
to baseline medical or treatment differences. This possibility was
not supported by univariate comparison of baseline AIDS-related
variables, as shown in Table 1, where there were no statistically
significant differences between the groups. Detailed analysis of
baseline variables differing at P < 0.20 did find that higher
baseline POMS scores were associated with greater improvement in
POMS scores over the course of the study. By chance, patients in
the treatment group showed more psychological distress at baseline,
so their improved mood over the study interval may represent simply
an effect of increased hope or expectation due to their participation
in an intervention research study. The additional finding that adjusting
for differences in baseline POMS caused a change in the direction
of the beneficial effect is difficult to understand and is likely
due to chance.
While baseline psychological state, as measured by the POMS, did
correlate with psychological outcomes, it did not correlate with
any of the medical outcomes.
TABLE 3-Distribution of AIDS-Related Illnesses Acquired
During the Study
Do am number of cases; presence or absence was based on medical
chard review.
Detailed examination of the effects of differences in baseline factors
on outcomes also found a marginal effect of difference in minority
status for hospitalizations.This is an interesting finding but is
weakened by the fact that in this study no minorities received DH.
In fact, when hospitalizations and hospital days are examined within
the control group alone, ethnicity does not make a significant difference.
Because our sample of minorities was so small and they all ended
up in the control group, the fact that they had proportionately
more hospitalizations is very hard to interpret. Adjustment for
their contributions has only a small effect on the P value, but
clearly a larger sample with more minorities would be required to
determine whether DH was affecting hospitalizations. It is important
to point out that having conducted 50 statistical tests to find
interactions between differences in baseline factors and outcomes
(excluding death), only two were found, which is the number expected
by chance. We found no' baseline differences with P < 0.20, which
could explain differences in number of doctor visits or number or
severity of new ADDs. Although there was a near-significant trend
for more smokers in the control group, by the study midpoint treatment
subjects who resumed smoking brought the distribution into better
balance. There was no correlation with smoking status and any study
outcome. It does remain possible, however, that combinations of
baseline variables or differences in some unmeasured variable may
have influenced outcomes.
A second possible explanation for the data is an expectation or
placebo effect, as when patient improvement occurs due to a belief
about the effectiveness of a treatment. 14,15 This is especially
worth examining given the finding that baseline psychological status
may have affected change in psychological well-being during this
study. The expectation effect should lead to better outcomes among
subjects who believe they were in the treatment group, regardless
of their true group assignment. Differences in medical outcomes
were related to true group assignment, however, and unrelated to
assignment belief The only outcome measure showing correlation with
subject belief was CD4+ count, and interestingly, this finding held
up only at the study midpoint and not at the end of the study. Possibly,
early in the study, subjects who believed they were in the treatment
group came to this belief because they knew from some other source
that their CD4+ count was rising. We cannot eliminate the possibility
that hope or expectation as reflected by the subject's guess may
have affected CD4+ count, but CD4+ count did not differ between
the two study groups, so it does not seem likely this factor affected
the differential study outcomes.
The findings of reduction in medical utilization and development
of fewer and less severe new illnesses suggest, as in the Byrd study,
a global rather than a specific DH effect. This study made an initial
attempt to identify a specific marker of DH action by including
CD4+ counts. Despite the differences in medical morbidity, however,
there were no significant differences between the groups in CD4+
counts, which generally remained very low. Recent evidence suggests
that viral load may be a better outcome predictor than CD4+ count."
Future studies should seek specific markers of DH effect with viral
load and natural killer cell activity.
Existing medical understanding offers no mechanism to account for
a finding of healing at a distance; however, science does not require
a known mechanism to prove the existence of a phenomenon. As pointed
out by Dossey,17 for years no one knew how colchicine, morphine,
aspirin, or quinine worked, yet they were known to be effective.
Hand-washing, too, became standard medical practice well before
a theory of infectious disease was described. Possible mechanisms
for DH might include some form of mind-to-mind communication between
patient and practitioner or some form of previously undescribed
energy transfer. Such concepts are, of course, highly speculative
and remain an area for future research. The finding of reduced medical
utilization and improved medical course in the DH group is both
exciting and surprising, but it remains crucial for this work to
be replicated to be more confident that the effect is real.
If the effect is robust, future studies will also need to compare
different DH techniques and investigate the efficacy of DH in different
illnesses and with different subject populations.
Acknowledgments
We thank G. Furst and R. Scott for their outstanding assistance
with data management and collection and Drs. J. Kaiser, D. Karasic,
and M. Cantwell for valuable discussions and suggestions. We especially
thank all of the healers who donated their skills and time and made
this project possible.
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