Efficacy and safety of acetaminophen in the treatment of migraine: results of a randomized, double-blind, placebo-controlled, population-based study

BACKGROUND

Although most persons with migraine treat their headaches with over-the-counter medication, systematic data on the safety and efficacy of widely used treatment, including acetaminophen, are sparse.

METHODS

This is a randomized, double-blind, placebo-controlled study comparing oral acetaminophen, 1000 mg (two 500-mg Extra Strength Tylenol tablets), with identical placebo in the treatment of a single acute migraine attack. Eligible subjects met International Headache Society diagnostic criteria for migraine with or without aura. Patients who usually required bed rest with their headaches or who vomited more than 20% of the time were excluded.

MAIN OUTCOME MEASURES

The percentage of subjects who, at 2 hours after dosing, experienced a change in baseline pain intensity from severe or moderate pain to mild or no pain (headache response); and pain intensity difference from baseline at the 2-hour postmedication assessment.

RESULTS

The headache response rate 2 hours after dosing was 57.8% in the acetaminophen group and 38.7% in the placebo group (P =.002). Pain-free rates at 2 hours were 22.4% in the acetaminophen group and 11.3% in the placebo group (P =.01). The mean pain intensity difference from baseline 2 hours after dosing was 1.08 in the acetaminophen group and 0.73 in the placebo group (P<.001). At 2 hours, other migraine headache characteristics, such as functional disability (P =.002), photophobia (P =.02), and phonophobia (P =.08), were significantly improved after treatment with acetaminophen vs placebo.

CONCLUSIONS

Acetaminophen was highly effective for treating pain, functional disability, photophobia, and phonophobia in a population-based sample of persons with migraine, excluding the most disabled persons with migraine. The drug also had an excellent safety profile and was well tolerated. Arch Intern Med. 2000;160:3486-3492.

Menstrual cycle and headache in a population sample of migraineurs

BACKGROUND

Migraine is three times more common in women than men. There is a clinical impression that migraines are more common and severe around the time of menses.

OBJECTIVES

To determine 1) the distribution of headache attacks by day of the menstrual cycle in women with migraine, 2) if the excess occurrence varies by headache type, and 3) if headache features differ by time in the menstrual cycle.

METHODS

In a population-based sample, 81 menstruating women with clinically diagnosed migraine were enrolled in a 98-day diary study and completed a total of 7219 diary days. The daily diary was used to record the occurrence of menses, headache days, and, on days with headache, associated headache features (i.e., symptoms, quality-of-pain, attack duration, pain intensity, and disability at work, household work, and nonwork activities).

RESULTS

An excess risk of headache occurred perimenstrually and was highest on days 0 and 1 of the cycle (day 0 being the first day of menses). A significantly elevated risk of headache on days 0 and 1 was observed for migraine without aura (OR 2.04; 95% CI 1.49, 2.81) and for tension-type headache (OR 1.67; 95% CI 1.24, 2.25). Elevated risks were also observed in the 2 days before onset of menses for migraine without aura (OR 1.80; 95% CI 1.40, 2.30). A significantly lower risk was observed around the time of ovulation for all headaches (OR 0.44; 95% CI 0.27, 0.72). Few significant differences were observed in headache features (i.e., pain intensity, disability score, symptom score, headache duration) by day of the cycle overall or by headache type. Pain intensity was slightly greater for migraine headaches during the first 2 days of menses.

CONCLUSIONS

Attacks of migraine without aura, but not migraine with aura, were more likely to occur 2 days before onset of menses and on the first 2 days of menses. This study does not support the clinical notion that headaches, regardless of type, are more severe during the perimenstrual period compared to other times in the cycle. Although migraine headaches are significantly more painful during the first 2 days of menses, differences are small.

Stratified care vs step care strategies for migraine: the Disability in Strategies of Care (DISC) Study: A randomized trial

CONTEXT

Various guidelines recommend different strategies for selecting and sequencing acute treatments for migraine. In step care, treatment is escalated after first-line medications fail. In stratified care, initial treatment is based on measurement of the severity of illness or other factors. These strategies for migraine have not been rigorously evaluated.

OBJECTIVE

To compare the clinical benefits of 3 strategies: stratified care, step care within attacks, and step care across attacks, among patients with migraine.

DESIGN AND SETTING

Randomized, controlled, parallel-group clinical trial conducted by the Disability in Strategies Study group from December 1997 to March 1999 in 88 clinical centers in 13 countries.

PATIENTS

A total of 835 adult migraine patients with a Migraine Disability Assessment Scale (MIDAS) grade of II, III, or IV were analyzed as the efficacy population; the safety analysis included 930 patients.

INTERVENTIONS

Patients were randomly assigned to receive (1) stratified care (n = 279), in which patients with MIDAS grade II treated up to 6 attacks with aspirin, 800 to 1000 mg, plus metoclopramide, 10 mg, and patients with MIDAS grade III and IV treated up to 6 attacks with zolmitriptan, 2.5 mg; (2) step care across attacks (n = 271), in which initial treatment was with aspirin, 800 to 1000 mg, plus metoclopramide, 10 mg. Patients not responding in at least 2 of the first 3 attacks switched to zolmitriptan, 2.5 mg, to treat the remaining 3 attacks; and (3) step care within attacks (n = 285), in which initial treatment for all attacks was with aspirin, 800 to 1000 mg, plus metoclopramide, 20 mg. Patients not responding to treatment after 2 hours in each attack escalated treatment to zolmitriptan, 2.5 mg.

MAIN OUTCOME MEASURES

Headache response, achieved if pain intensity was reduced from severe or moderate at baseline to mild or no pain at 2 hours; and disability time per treated attack at 4 hours for all 6 attacks, compared among the 3 groups.

RESULTS

Headache response at 2 hours was significantly greater across 6 attacks in the stratified care treatment group (52.7%) than in either the step care across attacks group (40.6%; P<.001) or the step care within attacks group (36.4%; P<.001). Disability time (6 attacks) was significantly lower in the stratified care group (mean area under the curve [AUC], 185.0 mm. h) than in the step care across attacks group (mean AUC, 209.4 mm. h; P<.001) or the step care within attacks group (mean AUC, 199.7 mm. h; P<.001). The incidence of adverse events was higher in the stratified care group (321 events) vs both step care groups (159 events in across-attack group; 217 in within-attack group), although most events were of mild-to-moderate intensity.

CONCLUSION

Our results indicate that as a treatment strategy, stratified care provides significantly better clinical outcomes than step care strategies within or across attacks as measured by headache response and disability time. JAMA. 2000;284:2599-2605.

2000 Wolfe Award. Sumatriptan for the range of headaches in migraine sufferers: results of the Spectrum Study

BACKGROUND

Migraineurs experience a spectrum of headaches: migraine, migrainous, and episodic tension-type as defined by the International Headache Society (IHS).

OBJECTIVE

To evaluate the effectiveness of sumatriptan, 50-mg tablets, in treating the spectrum of headaches in IHS-diagnosed migraineurs.

DESIGN/METHODS

Migraineurs with severe disability (Headache Impact Questionnaire score 250 or greater) were enrolled in a randomized, double-blind, placebo-controlled, crossover study. Patients treated up to 10 headaches with sumatriptan, 50 mg, or placebo (4:1). Headache features, recorded prior to treatment, were used to classify each headache using IHS criteria. Headache response (moderate or severe pain reduced to mild or no pain) and pain-free response were recorded at 2 and 4 hours postdose (primary endpoint). Because patients treated multiple attacks, statistical methods controlling for within-subject correlation were used.

RESULTS

Two hundred forty-nine migraineurs treated 1576 moderate or severe headaches: migraine (n = 1110), migrainous (n = 103), and tension-type (n = 363). Sumatriptan was superior to placebo for headache response 4 hours postdose (primary endpoint) across all headache types (migraine, 66% versus 48%; P<.001; migrainous, 71% versus 39%; P<.01; tension-type, 78% versus 50%, P<.001). Sumatriptan was also superior to placebo for pain-free response 4 hours postdose for migraine (41% versus 24%, P<.001) and tension-type headaches (56% versus 36%, P =.001). Sumatriptan provided superior pain-free response 2 hours postdose for migraine (18% versus 7%, P<.0001) and tension-type headache (28% versus 14%, P =.0005) compared with placebo.

CONCLUSION

Sumatriptan, 50-mg tablets, are effective for the full spectrum of headaches experienced by patients with disabling migraine due to a sumatriptan-responsive mechanism.

Treatment of mild headache in disabled migraine sufferers: results of the Spectrum Study

OBJECTIVE

To evaluate the effectiveness of sumatriptan, 50-mg tablets, versus placebo for early intervention while head pain was mild in patients with disabling migraine.

METHODS

A post hoc analysis was performed in a subgroup of patients from a large, randomized, placebo-controlled study of patients with disabling headache who treated while pain was mild. Pain-free response 2 and 4 hours postdose, headache recurrence, and safety were examined. Significance tests were performed only for the first-treated attacks.

RESULTS

Twenty-six patients with disabling headache treated 46 mild and 166 moderate or severe headaches. For the first-treated headaches while pain was mild, pain-free rates were significantly higher for sumatriptan than placebo 4 hours postdose (78% versus 0%, P =.02), but not 2 hours postdose (52% versus 0%, P =.22). Across all headaches treated while pain was mild, pain-free responses were higher for sumatriptan than placebo 4 hours (85% versus 17%) and 2 hours (50% versus 0%) postdose compared with placebo. When the same patients treated headaches while pain was moderate or severe, pain-free rates were lower than that reported for treatment during mild pain. There was a trend toward lower headache recurrence in headaches treated while pain was mild compared with moderate or severe pain (13% versus 18%). No drug-related adverse events were reported in the headaches treated while pain was mild.

CONCLUSIONS

Patients with disabling migraine may benefit from early intervention with sumatriptan, 50 mg, while pain is mild.

Past adult lead exposure is associated with longitudinal decline in cognitive function

OBJECTIVE

To determine whether adults with past exposure to neurotoxicants have progressive declines in cognitive function years after exposure has ceased, and whether tibia lead is a predictor of the magnitude of change.

METHODS

A total of 535 former organolead manufacturing workers with a mean age of 55.6 years, a mean duration of 16 years since last occupational lead exposure, and low blood lead levels at the first study visit and 118 controls were evaluated with neurobehavioral tests two to four times over 4 years. "Peak" tibia lead levels, estimated from current levels measured by X-ray fluorescence, were used to predict changes in cognitive function over time.

RESULTS

In former lead workers, peak tibia lead ranged from -2.2 to 98.7 microg Pb/g bone mineral. Compared to controls, former lead workers performed worse over time for three tests of visuo-constructive ability and verbal memory and learning (p < 0.05). In former lead workers, peak tibia lead predicted declines for six tests of verbal memory and learning, visual memory, executive ability, and manual dexterity (p < 0.05 for four tests and < 0.10 for two additional tests). On average, for these six tests, an increase of 15.7 microg/g of peak tibia lead was equivalent in its effects on annual test decline to 5 more years of age at baseline.

CONCLUSIONS

These are the first data to suggest that cognitive function can progressively decline due to past occupational exposures to a neurotoxicant.

Associations of blood lead, dimercaptosuccinic acid-chelatable lead, and tibia lead with polymorphisms in the vitamin D receptor and [delta]-aminolevulinic acid dehydratase genes

A cross-sectional study was performed to evaluate the influence of polymorphisms in the [delta]-aminolevulinic acid dehydratase (ALAD) and vitamin D receptor (VDR) genes on blood lead, tibia lead, and dimercaptosuccinic acid (DMSA)-chelatable lead levels in 798 lead workers and 135 controls without occupational lead exposure in the Republic of Korea. Tibia lead was assessed with a 30-min measurement by (109)Cd-induced K-shell X-ray fluorescence, and DMSA-chelatable lead was estimated as 4-hr urinary lead excretion after oral administration of 10 mg/kg DMSA. The primary goals of the analysis were to examine blood lead, tibia lead, and DMSA-chelatable lead levels by ALAD and VDR genotypes, controlling for covariates; and to evaluate whether ALAD and VDR genotype modified relations among the different lead biomarkers. There was a wide range of blood lead (4-86 microg/dL), tibia lead (-7-338 microg Pb/g bone mineral), and DMSA-chelatable lead (4.8-2,103 microg) levels among lead workers. Among lead workers, 9.9% (n = 79) were heterozygous for the ALAD(2) allele and there were no homozygotes. For VDR, 10.7% (n = 85) had the Bb genotype, and 0.5% (n = 4) had the BB genotype. Although the ALAD and VDR genes are located on different chromosomes, lead workers homozygous for the ALAD(1) allele were much less likely to have the VDR bb genotype (crude odds ratio = 0.29, 95% exact confidence interval = 0.06-0.91). In adjusted analyses, subjects with the ALAD(2) allele had higher blood lead levels (on average, 2.9 microg/dL, p = 0.07) but no difference in tibia lead levels compared with subjects without the allele. In adjusted analyses, lead workers with the VDR B allele had significantly (p < 0.05) higher blood lead levels (on average, 4.2 microg/dL), chelatable lead levels (on average, 37.3 microg), and tibia lead levels (on average, 6.4 microg/g) than did workers with the VDR bb genotype. The current data confirm past observations that the ALAD gene modifies the toxicokinetics of lead and also provides new evidence that the VDR gene does so as well.

Migraine, quality of life, and depression: a population-based case-control study

OBJECTIVE

This study reports on the influence of migraine and comorbid depression on health-related quality of life (HRQoL) in a population-based sample of subjects with migraine and nonmigraine controls.

METHODS

Two population-based studies of similar design were conducted in the United States and United Kingdom. A clinically validated, computer-assisted telephone interview was used to identify individuals with migraine, as defined by the International Headache Society, and a nonmigraine control group. During follow-up interviews, 389 migraine cases (246 US, 143 UK) and 379 nonmigraine controls (242 US, 137 UK) completed the Short Form (SF)-12, a generic HRQoL measure, and the Primary Care Evaluation of Mental Disorders, a mental health screening tool. The SF-12 measures HRQoL in two domains: a mental health component score (MCS-12) and a physical health component score (PCS-12).

RESULTS

In the United States and United Kingdom, subjects with migraine had lower scores (p < 0.001) on both the MCS-12 and PCS-12 than their nonmigraine counterparts. Significant differences were maintained after controlling for gender, age, and education. Migraine and depression were highly comorbid (adjusted prevalence ratio 2.7, 95% CI 2.1 to 3. 5). After adjusting for gender, age, and education, both depression and migraine remained significantly and independently associated with decreased MCS-12 and PCS-12 scores. HRQoL was significantly associated with attack frequency (for MCS-12 and PCS-12) and disability (MCS-12).

CONCLUSIONS

Subjects with migraine selected from the general population have lower HRQoL as measured by the SF-12 compared with nonmigraine controls. Further, migraine and depression are highly comorbid and each exerts a significant and independent influence on HRQoL.

A change point model for estimating the onset of cognitive decline in preclinical Alzheimer's disease

Dementia is characterized by accelerated cognitive decline before and after diagnosis as compared to normal ageing. Determining the time at which that rate of decline begins to accelerate in persons who will develop dementia is important both in describing the natural history of the disease process and in identifying the optimal time window for which treatments might be useful. We model that time at which the rate of decline begins to accelerate in persons who develop dementia relative to those who do not by using a change point in a mixed linear model. A profile likelihood method is proposed to draw inferences about the change point. The method is applied to data from the Bronx Ageing Study, a cohort study of 488 initially non-demented community-dwelling elderly individuals who have been examined at approximately 12-month intervals over 15 years. Cognitive function was measured using the Buschke Selective Reminding test, a memory test with high reliability and known discriminative validity for detecting dementia. We found that the rate of cognitive decline as measured by this test in this cohort increases on average 5.1 years before the diagnosis of dementia.

Abdominal pain, bloating, and diarrhea in the United States: prevalence and impact

The prevalence and impact of abdominal pain, bloating, and diarrhea in the adult US population are largely unknown. We conducted a national, cross-sectional, telephone survey of US households to provide estimates of the frequency, duration, severity, and impact of specific digestive symptoms during the previous month. A total of 2510 subjects completed interviews (70.7% response rate). Among the respondents, 1017 (40.5%) reported one or more digestive symptoms within the month before the interview, including abdominal pain or discomfort 21.8%, bloating or distension 15.9%, and diarrhea or loose stools 26.9%. Women were more likely than men to report abdominal pain or discomfort (24.4% vs 17.5%) and bloating or distension (19.2% vs 10.5%), but not diarrhea or loose stools (27.1% vs 26.7%). Symptoms were less common among those > or =60 years of age. More than 65% of respondents rated symptoms as moderate or severe in intensity, and the majority reported limitations in daily activities. We conclude that digestive symptoms are more common than previously recognized and have a significant impact.

Evaluation of a novel solubilized formulation of ibuprofen in the treatment of migraine headache: a randomized, double-blind, placebo-controlled, dose-ranging study

A total of 729 migraine sufferers with moderate to severe baseline pain evaluated a single 200, 400 or 600 mg dose of a new liquigel formulation of ibuprofen over 8 h. Ibuprofen liquigels were significantly superior to placebo for cumulative headache response (pain reduced to mild or none) from 0.5 (600 mg) or 1 h (200 and 400 mg) to 8 h. At 2 h, respective headache response rates for ibuprofen 200, 400 and 600 mg and placebo were 64%, 72%, 72% and 50%. All three doses were also significantly superior to placebo for 2-h pain-free (25%, 28%, 29% and 13%, respectively) and for proportions with mild or no limitation of activity (2-8 h). Ibuprofen liquigels were generally superior to placebo for reducing photophobia, phonophobia, or nausea (1-4 h) and for global evaluation. All doses were well tolerated. These data demonstrate that ibuprofen liquigels relieve the pain, ancillary symptoms, and limitation of activity, of migraine.

Different associations of blood lead, meso 2,3-dimercaptosuccinic acid (DMSA)-chelatable lead, and tibial lead levels with blood pressure in 543 former organolead manufacturing workers

In this study, the authors' objective was to determine the influence of blood lead, meso 2,3-dimercaptosuccinic acid (DMSA)-chelatable lead, and tibial lead on systolic and diastolic blood pressures and on hypertension in 543 former organolead manufacturing workers. All workers had past exposure to inorganic and organic lead. The authors used linear regression to model systolic and diastolic blood pressure separately, and logistic regression was used for the modeling of hypertension status (i.e., systolic blood pressure > 160 mm Hg, diastolic blood pressure > or =96 mm Hg, or current use of antihypertensive medications). Blood lead, DMSA-chelatable lead, and tibial lead levels had means (standard deviations appear within parentheses) of 4.6 microg/dl (2.6 microg/dl), 19.3 microg (17.2 microg), and 14.4 microg/g (9.3 microg/g), respectively. The authors adjusted for covariates, and they found that blood lead was a predictor of (1) both systolic and diastolic blood pressures and (2) hypertension status in men < 58 y of age. DMSA-chelatable lead and tibial lead were not associated with any of the blood pressure measures. Systolic blood pressure was elevated by blood lead levels as low as 5 microg/dl. We speculate that lead may have a transient influence on blood pressure that is related to target dose levels obtained once release of lead from body stores has occurred.

Associations of tibial lead levels with BsmI polymorphisms in the vitamin D receptor in former organolead manufacturing workers

We evaluated associations of tibial lead levels with polymorphisms in the vitamin D receptor (VDR) in 504 former organolead manufacturing workers with past exposure to lead. In this cross-sectional study, we measured tibial lead by (109)Cd K-shell X-ray fluorescence. Tibial lead was evaluated in subjects with different VDR genotypes defined using the BsmI restriction enzyme, adjusting for confounding variables. Study participants had a mean age +/- SD of 57.4 +/- 7.6 years. A total of 169 (33.5%) subjects were homozygous for the BsmI restriction site (designated bb), 251 (49.8%) were heterozygous (Bb), and 84 (16.7%) were homozygous for the absence of the restriction site (BB). Among all of the study subjects, tibial lead concentrations were low, with a mean +/- SD of 14.4 +/- 9.3 microg Pb/g bone mineral. There were only small differences in tibial lead concentrations by VDR genotype, with mean +/- SD tibial lead concentrations of 13.9 +/- 7.9, 14.3 +/- 9.5, and 15.5 +/- 11.1 in subjects with bb, Bb, and BB, respectively. In a multiple linear regression model of tibial lead concentrations, the VDR genotype modified the relation between age and tibial lead concentrations; subjects with the B allele had larger increases in tibial lead concentrations with increasing age (0.37, 0.48, and 0.67 microg/g per year of age in subjects with bb, Bb, and BB, respectively; the adjusted p-value for trend in slopes = 0.04). The VDR genotype also modified the relation between years since last exposure to lead and tibial lead concentrations. Subjects with bb evidenced an average decline in tibial lead concentrations of 0.10 microg/g per year since their last exposure to lead, whereas subjects with Bb and BB evidenced average increases of 0.03 and 0.11 microg/g per year, respectively (the adjusted p-value for trend in slopes = 0.01). Polymorphisms in the vitamin D receptor modified the relations of age and years since the last exposure to lead with tibial lead concentrations. Although controversy remains on the influence of the VDR genotype on bone mineral density, the data suggest that variant VDR alleles modify lead concentrations in bone, either by influencing lead content or calcium content or both.

Upper gastrointestinal symptoms in a U.S. national sample of adults with diabetes

BACKGROUND

Individuals with diabetes may be particularly susceptible to motility-related upper gastrointestinal (UGI) symptoms such as abdominal pain or discomfort, bloating, early satiety, nausea, and vomiting. We estimated the prevalence of UGI symptoms in a population-based sample of individuals with diabetes and determined whether cases and population controls differed in prevalence of UGI symptoms and in symptom features.

METHODS

Individuals with diabetes (n = 483) and matched controls (n = 422) were recruited from a prior U.S. national health survey for a telephone interview on UGI symptoms. To confirm self-reported diabetes status, cases provided information on clinical management measures. Subjects were asked about UGI symptoms in the month before interview. Affirmative responses to initial questions triggered detailed questions about symptom frequency, timing, duration, and severity. Differences between cases and controls were evaluated.

RESULTS

Cases not only had a significantly (P < 0.05) higher overall prevalence of one or more UGI symptoms in the past month (50%) than controls (38%), but they also reported a significantly greater number of UGI symptoms than controls. Almost 10% of cases reported three or more UGI symptoms in the past month compared with 2% of controls. Our study also identified UGI symptom features that were more relevant to cases and showed that one UGI symptom, heartburn, co-occurred significantly more often with UGI symptoms in cases than in controls.

CONCLUSIONS

Upper GI symptoms are common in individuals with diabetes and more prevalent than in controls. The symptoms are non-specific and may reflect disruptions in motility or perception.

Headache and major depression: is the association specific to migraine?

OBJECTIVE

To examine the relationship between migraine and major depression, by estimating the risk for first-onset major depression associated with prior migraine and the risk for first migraine associated with prior major depression. We also examined the extent to which comorbidity with major depression is specific to migraine or is observed in other severe headaches.

METHODS

Representative samples of persons 25 to 55 years of age with migraine or other severe headaches (i.e., disabling headaches without migraine features) and controls with no history of severe headaches were identified by a telephone survey and later interviewed in person to ascertain history of common psychiatric disorders.

RESULTS

Lifetime prevalence of major depression was approximately three times higher in persons with migraine and in persons with severe headaches compared with controls. Significant bidirectional relationships were observed between major depression and migraine, with migraine predicting first-onset depression and depression predicting first-onset migraine. In contrast, persons with severe headaches had a higher incidence of first-onset major depression (hazard ratio = 3.6), but major depression did not predict a significantly increased incidence of other severe headaches (hazard ratio = 1.6).

CONCLUSIONS

The contrasting results regarding the relationship of major depression with migraine versus other severe headaches suggest that different causes may underlie the co-occurrence of major depression in persons with migraine compared with persons with other severe headaches.

Epidemiology of constipation (EPOC) study in the United States: relation of clinical subtypes to sociodemographic features

OBJECTIVE

Constipation is a common heterogeneous condition, possibly encompassing different clinical subtypes. Little is known about the comparative epidemiology of constipation subtypes. This study was conducted to estimate the prevalence of constipation subtypes and determine whether subtypes differ by sociodemographic factors.

METHODS

Between June and September 1997, a telephone interview was conducted with individuals about their bowel habits in the preceding 3 months. Survey data on 15 constipation-related symptoms were used to identify individuals who met prespecified symptom criteria for the following mutually exclusive subgroups: functional constipation, irritable bowel syndrome (IBS), outlet obstruction or delay (outlet), both IBS and outlet (IBS-outlet), and frequent laxative users (i.e., at least every other day). A total of 10,018 eligible individuals in the United States 18 yr of age or older completed the interview. Test-retest reliability of reporting symptoms was assessed in a separate national survey. The Spearman's correlation coefficient for reporting symptoms ranged from 0.54 to 0.83; all but three symptoms had correlations above 0.68.

RESULTS

The overall prevalence of constipation was 14.7%. By subtype, prevalence was 4.6% for functional, 2.1% for IBS, 4.6% for outlet, and 3.4% for IBS-outlet. An additional 1.8% of respondents reported laxative use at least every other day. Outlet was the most common subtype among women, whereas functional constipation was the most common subtype among men. The gender ratio varied by subtype, with elevated ratios for outlet (F/M = 1.65) and IBS-outlet (F/M = 2.27) subtypes. The age pattern differed among each of the four subtypes. Prevalence of functional subtype decreased with increasing age. In contrast, outlet subtype did not seem to vary by age, and IBS (both men and women) and IBS-outlet (women only) subtypes increased to age 35 yr and declined thereafter. Prevalence of functional constipation increased with increasing education. Outlet type was more common in nonwhites compared to whites. Finally, 45% of individuals with constipation reported having the condition for 5 yr or more.

CONCLUSIONS

Constipation is a heterogeneous condition. Differences in epidemiological profile by age, sex ratio, and relation to other sociodemographical factors support the distinction of two and possibly more symptom-based subtypes.

Modelling disease progression in terms of exposure history

We consider the relationship between accumulating exposure to a putative agent and the associated change in physiologic function. This type of problem is common to prospective studies of cognitive, pulmonary and cardiovascular function. A general model is proposed for data from prospective, observational studies with concurrent measures of exposures and continuous outcome measures. This model permits non-linearity in the relationship between exposure and outcome and is designed to describe outcome in terms of one's entire exposure history. As exposure data are often severely right-skewed, we use regression spline estimation methods which localize the influence of extreme points. We illustrate our methodology using data from a longitudinal epidemiologic investigation of the effects of amateur boxing on neuropsychologic function.

An international study to assess reliability of the Migraine Disability Assessment (MIDAS) score

BACKGROUND

The Migraine Disability Assessment (MIDAS) instrument is a five-item questionnaire developed to measure headache-related disability and improve doctor-patient communication about the functional consequences of migraine.

OBJECTIVES

To examine the test-retest reliability and internal consistency of the five items and of the overall MIDAS score in population-based samples of migraine sufferers in two countries and to compare consistency across countries.

METHODS

Using a clinically validated telephone interview, population-based samples of migraine-headache sufferers were identified in the United States (Baltimore, MD) and the United Kingdom (Merton and Sutton, Surrey). Eligible individuals completed the MIDAS questionnaire on two occasions an average of 3 weeks apart. The MIDAS score is derived from five questions about missed time from work and household work (one question each about missed days and days with at least 50% reduced productivity) and missed days of nonwork activities.

RESULTS

A total of 97 migraine-headache sufferers from the United States and 100 from the United Kingdom completed the MIDAS questionnaire twice. Mean and median item values and overall MIDAS scores were similar between the United States and the United Kingdom. Test-retest Spearman correlations of individual items ranged from 0.46 to 0.78. No significant differences in item-specific correlations were observed between the United States and United Kingdom. The test-retest Pearson correlation of the MIDAS score (i.e., sum of lost days and reduced-effectiveness days in each domain) was 0.80 in the United States and 0.83 in the United Kingdom. The Cronbach alpha, a measure of internal consistency, was 0.76 in the United States and 0.73 in the United Kingdom.

CONCLUSIONS

This is the first international population-based study to assess the reliability of a disability-related illness severity score for migraine. The reliability and internal consistency of the Migraine Disability Assessment score are similar to that of a previous questionnaire (Headache Impact Questionnaire). However, the Migraine Disability Assessment score requires fewer questions, is easier to score, and provides intuitively meaningful information on lost days of activity in three domains.

Neurobehavioral function and tibial and chelatable lead levels in 543 former organolead workers

OBJECTIVE

To evaluate the associations between tibial lead, dimercaptosuccinic acid (DMSA)-chelatable lead, and neurobehavioral function in former organolead manufacturing workers with past exposure to organic and inorganic lead.

METHODS

Data were collected from 543 subjects with a mean age of 58 years and an average of 17.8 years since last lead exposure. Years since last exposure to lead was used to estimate tibial lead levels in the year of last occupational lead exposure, termed "peak tibial lead." Current tibial lead levels, measured by x-ray fluorescence, were extrapolated back using a clearance half-time of lead in tibia of 27 years, assuming first-order clearance from tibia.

RESULTS

Peak tibial lead levels ranged from -2.2 to 105.9 microg Pb/g bone mineral, and DMSA-chelatable lead levels were between 1.2 and 136 microg. After adjustment for confounding variables, peak tibial lead was a significant negative predictor of performance on the Wechsler Adult Intelligence Scale-Revised vocabulary subtest (p = 0.02), serial digit learning test (p = 0.04), Rey Auditory-Verbal Learning Test (immediate recall and recognition, p = 0.03 for each), Trail Making Test B (p = 0.03), finger tapping (dominant hand [p = 0.02] and nondominant hand [p < 0.01]), Purdue pegboard (dominant hand, nondominant hand, both hands, and assembly, p < 0.01 for each), and Stroop Test (p < 0.01). Moreover, with one exception, average neurobehavioral test scores were poorer at higher peak tibial lead levels. DMSA-chelatable lead was only significantly associated with choice reaction time (p = 0.01).

CONCLUSION

Peak tibial lead was consistently associated with poorer neurobehavioral test scores, particularly in the domains of manual dexterity, executive ability, verbal intelligence, and verbal memory.

Burden of migraine in the United States: disability and economic costs

BACKGROUND

Migraine is a common disabling disease but its economic burden has not been adequately quantified.

OBJECTIVE

To estimate the burden of migraine in the United States with respect to disability and economic costs.

METHODS

The following data sources were used: published data, the Baltimore County Migraine Study, MEDSTAT's MarketScan medical claims data set, and statistics from the Census Bureau and the Bureau of Labor Statistics. Disability was expressed as bedridden days. Charges for migraine-related treatment were used as direct cost inputs. The human capital approach was used in the estimation of indirect costs.

RESULTS

Migraineurs required 3.8 bed rest days for men and 5.6 days for women each year, resulting in a total of 112 million bedridden days. Migraine costs American employers about $13 billion a year because of missed workdays and impaired work function; close to $8 billion was directly due to missed workdays. Patients of both sexes aged 30 to 49 years incurred higher indirect costs compared with younger or older employed patients. Annual direct medical costs for migraine care were about $1 billion and about $100 was spent per diagnosed patient. Physician office visits accounted for about 60% of all costs; in contrast, emergency department visits contributed less than 1% of the direct costs.

CONCLUSIONS

The economic burden of migraine predominantly falls on patients and their employers in the form of bedridden days and lost productivity. Various screening and treatment regimens should be evaluated to identify opportunities to reduce the disease burden.

Treatment of menstruation-associated migraine with the nonprescription combination of acetaminophen, aspirin, and caffeine: results from three randomized, placebo-controlled studies

This retrospective study sought to examine the benefits of the nonprescription combination of acetaminophen, aspirin, and caffeine (AAC; Excedrin Migraine, Bristol-Myers Squibb Company, New York, New York) for the treatment of menstruation-associated migraine compared with migraine not associated with menses. Data were derived from 3 double-masked, randomized, placebo-controlled, single-dose trials enrolling subjects who met the International Headache Society's diagnostic criteria for migraine with or without aura. Subjects with incapacitating disability (attacks requiring bed rest >50% of the time) and those who usually experienced vomiting > or =20% of the time were excluded. Retrospective analysis of the 1220 subjects included in the efficacy-evaluable data set indicated that 185 women treated menstruation-associated migraine, 781 women treated migraine not associated with menses, and 1 woman provided no information regarding menstrual status. At baseline and at 0.5, 1, 2, 3, 4, and 6 hours postdose, subjects assessed the intensity of headache pain, functional disability, nausea, photophobia, and phonophobia. Pain intensity, nausea, photophobia, and phonophobia were rated on a 4-point scale ranging from 0 = none to 3 = severe; functional disability was rated on a 5-point scale ranging from 0 = none to 4 = incapacitating. For both menstruation-associated migraine and migraine not associated with menses, the proportion of subjects with pain intensity reduced to mild or none (responders) was significantly greater with AAC than with placebo at all postdose time points from 0.5 through 6 hours (P< or =0.05), with no statistically significant difference in treatment effect between menstruation-associated migraine and migraine not associated with menses at any postdose time point. Migraine characteristics such as photophobia, phonophobia, and functional disability were significantly improved in AAC-treated subjects at all time points from 1 through 6 hours (P< or =0.01) in both the menstruating and nonmenstruating groups. Significant relief from nausea was experienced in both menstruation-associated migraine and migraine not associated with menses, but relief appeared earlier in the AAC nonmenstruating subjects (2 hours postdose, P< or =0.01) than in the menstruating subjects (6 hours postdose, P< or =0.05). Beginning at 3 hours postdose, significantly fewer subjects treated with AAC required rescue medication (P< or =0.05) for menstruation-associated migraine (AAC 6%, placebo 15%) and migraine not associated with menses (AAC 7%, placebo 14%). The most commonly used rescue medications in both the menstruating and nonmenstruating groups were nonsteroidal anti-inflammatory drugs, prescription combination analgesics/narcotics, and prescription migraine preparations. AAC was well tolerated in both menstruation-associated migraine and migraine not associated with menses; in general, adverse experiences were similar in both groups. The proportion of subjects who had 1 or more adverse experiences was significantly higher among those receiving AAC than among those receiving placebo (menstruation-associated migraine: AAC 26.4%, placebo 12.6%, P = 0.025; nonmenstruation-associated migraine: AAC 18.6%, placebo 11.4%, P = 0.005). Adverse experiences were similar in type and severity to those previously associated with single doses of acetaminophen, aspirin, or caffeine. Thus the nonprescription combination of AAC was highly effective in treating the pain, disability, and associated symptoms of both menstruation-associated migraine and migraine not associated with menses.

Reliability of the migraine disability assessment score in a population-based sample of headache sufferers

BACKGROUND

The Migraine Disability Assessment (MIDAS) score is used to quantify headache-related disability. In a previous study, we showed that the MIDAS score was highly reliable in population-based samples of migraine headache sufferers in two countries.

OBJECTIVES

To examine the test-retest reliability and internal consistency of the five items comprising the MIDAS score and the overall MIDAS score in a population-based sample of both migraine and nonmigraine headache sufferers.

METHODS

Using a clinically validated telephone interview, a population-based sample of migraine and nonmigraine headache sufferers was identified in Baltimore, Maryland, USA. A total of 97 migraine cases and 80 nonmigraine subjects completed the MIDAS questionnaire on two occasions an average of 3 weeks apart. The MIDAS score is derived from five questions about missed time from work (or school) and household work (one question each about missed days and days with at least 50% reduced productivity) and missed days of nonwork activities.

RESULTS

Among all headache sufferers the test-retest Spearman's correlations of individual MIDAS questions ranged from 0.67 to 0.73. The Spearman's correlation for the MIDAS score (i.e., sum of lost days and reduced effectiveness days in each domain) was 0.84. Cronbach's alpha, a measure of internal consistency, was 0.83. Mean and median item values and the overall MIDAS scores differed between migraine and nonmigraine cases. Even after adjusting for differences in headache frequency, the mean MIDAS scores differed substantially (i.e., 10.3 points) between migraine cases and nonmigraine cases.

CONCLUSIONS

The reliability and internal consistency of the MIDAS score are high, as tested in a population-based sample of headache sufferers. MIDAS scores are substantially higher in migraine cases than in non-migraine cases, supporting the validity of the measure.

Validity of an illness severity measure for headache in a population sample of migraine sufferers

The headache impact questionnaire (HImQ) is used to measure pain and activity limitations from headache over a 3-month recall period. In a prior study, the test-retest reliability of the eight-item HImQ score was found to be relatively high (0.86). In the current study, we examined the validity of the eight-item HImQ by comparing the overall score and individual items to equivalent measures from a 90-day diary. Pain and activity limitations due to headache were assessed in a population-based sample of 132 migraine headache sufferers enrolled in a 90-day daily diary study who completed the HImQ at the end of the study. The HImQ score was derived from four frequency-based questions (i.e. number of headaches, missed days of work, missed days of chores, or missed days of non-work activity) and four summary measures of average experience across headaches (i.e. average pain intensity, and average reduced effectiveness when having a headache at work, during household chores, and in non-work activity). Diary based measures were used as the gold standard in evaluating the HImQ score. Mean and median values of frequency-based HImQ items (e.g. number of headaches) were similar to equivalent diary measures, indicating no systematic bias. In contrast, HImQ measures of average experience across attacks (e.g. average pain intensity) overestimated equivalent diary measures and, in general, better approximated diary measures for migraine headaches, rather than all headaches. The highest correlations between HImQ and diary items were observed for headache frequency and average pain intensity, the two general headache measures, followed by measures of reduced effectiveness. Among frequency-based measures, the strength of the correlation was directly related to the magnitude of the mean. The higher the mean value, the higher the correlation. The correlation between the HImQ score and diary based score was 0.49. The HImQ score is moderately valid. Frequency-based items (e.g. number of missed work days) were found to be unbiased and the highest correlation coefficients were observed for frequency-based items with relatively high mean counts (number of headaches, number of missed non-work days). These findings have implications for measuring severity of chronic episodic conditions like headache, asthma, back pain, arthritis, epilepsy, and panic disorder, which can cause limitations to activities. The validity of illness severity measures may be improved by using frequency-based questions to assess both missed activity days and days with significantly reduced effectiveness or productivity (e.g. by 50% or more). By combining the count for both missed days and days where productivity is substantially reduced, the mean of the frequency-based measure will be increased, a factor which may improve the overall validity of the item. A severity measure can be derived from such items by simple addition and provides a scale with intuitively meaningful units.

Screening for dementia with the memory impairment screen

OBJECTIVES

To validate a sensitive and specific screening test for AD and other dementias, assess its reliability and discriminative validity, and present normative data for its use in various applied settings.

BACKGROUND

To improve discrimination in screening for AD and dementia, we developed the Memory Impairment Screen (MIS), a 4-minute, four-item, delayed free- and cued-recall test of memory impairment. The MIS uses controlled learning to ensure attention, induce specific semantic processing, and optimize encoding specificity to improve detection of dementia.

METHODS

Equivalent forms of the MIS were given at the beginning and end of the testing session to assess alternate forms reliability. Discriminative validity was assessed in a criterion sample of 483 aged individuals, 50 of whom had dementia according to Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised) criteria.

RESULTS

The MIS had good alternate forms reliability, high construct validity for memory impairment, and good discriminative validity in terms of sensitivity, specificity, and positive predictive value. We present normative data for use in settings with different base rates (prevalences) of AD and dementia.

CONCLUSION

The MIS provides efficient, reliable, and valid screening for AD and other dementias.

Predictors of dimercaptosuccinic acid chelatable lead and tibial lead in former organolead manufacturing workers

OBJECTIVES

To identify predictors of tibial and dimercaptosuccinic acid (DMSA) chelatable lead in 543 organolead manufacturing workers with past exposure to organic and inorganic lead.

METHODS

In this cross sectional study, tibial lead (by 109Cd K-shell x ray fluorescence), DMSA chelatable lead (4 hour urinary lead excretion after oral administration of 10 mg/kg), and several exposure measures were obtained on study participants, mean (SD) age 57.6 (7.6) years.

RESULTS

Tibial lead concentrations ranged from -1.6 to 52.0 micrograms lead/g bone mineral, with a mean (SD) of 14.4 (9.3) micrograms/g. DMSA chelatable lead ranged from 1.2 to 136 micrograms, with a mean (SD) of 19.3 (17.2) micrograms. In a multiple linear regression model of tibial lead, age (p < 0.01), duration of exposure (p < 0.01), current (p < 0.01) and past (p = 0.05) cigarette smoking, and diabetes (p = 0.01) were all independent positive predictors, whereas height (p = 0.03), and exercise inducing sweating (p = 0.04) were both negative predictors. The final regression model accounted for 31% of the variance in tibial lead concentrations; 27% was explained by age and duration of exposure alone. DMSA chelatable lead was directly associated with tibial lead (p = 0.01), cumulative exposure to inorganic lead (y.microgram/m3, p = 0.01), current smoking (p < 0.01), and weight (p < 0.01), and negatively associated with diabetes (p = 0.02). The final model accounted for 11% of the variance in chelatable lead. When blood lead was added to this model of DMSA chelatable lead, tibial lead, cumulative exposure to inorganic lead, and diabetes were no longer significant; blood lead accounted for the largest proportion of variance (p < 0.001); and the total model r2 increased to 19%.

CONCLUSIONS

The low proportions of variance explained in models of both tibial and chelatable lead suggest that other factors are involved in the deposition of lead in bone and soft tissue. In epidemiological studies of the health effects of lead, evaluation of associations with both these measures may allow inferences to be made about whether health effects are likely to be recent, and thus potentially reversible, or chronic, and thus possibly irreversible. The data also provide direct evidence that in men the total amount of lead in the body that is bioavailable declines with age.