Valter Sundh

A placebo-controlled trial of a pertussis-toxoid vaccine.

BACKGROUND Although many whole-cell vaccines have been effective in preventing pertussis, these vaccines are difficult to standardize and can produce side effects. In Sweden, pertussis became endemic during the 1970s despite vaccination. Because of its limited efficacy, the Swedish-made whole-cell vaccine was withdrawn in 1979. METHODS To evaluate the efficacy of an acellular vaccine consisting of pertussis toxin inactivated by hydrogen peroxide (pertussis toxoid), we conducted a randomized, double-blind, placebo-controlled trial in Sweden. Infants were vaccinated with either diphtheria and tetanus toxoids alone (DT toxoids, 1726 infants) or diphtheria, tetanus, and pertussis toxoids (DTP toxoids, 1724 infants) at 3, 5, and 12 months of age. RESULTS There were no serious reactions. With the pertussis vaccine there were slightly more local reactions than with the DT toxoids alone, but the rates of postvaccination fever were the same. The main period of surveillance, which began 30 days after the third vaccination, continued for a median of 17.5 months. There were 312 cases of pertussis (72 in the DTP-toxoids group and 240 in the DT-toxoids group) that met the clinical criterion (paroxysmal cough lasting > or = 21 days) and laboratory criteria for pertussis as defined by the World Health Organization. The efficacy of this acellular vaccine was 71 percent (95 percent confidence interval, 63 to 78 percent). The recipients of DTP toxoids who had pertussis had cough of shorter duration than the recipients of DT toxoids, and fewer had whooping and vomiting. The vaccine efficacy after two doses was 55 percent (95 percent confidence interval, 12 to 78 percent), on the basis of 14 cases in the DTP-toxoids group and 31 in the DT-toxoids group that met the definition of the World Health Organization. CONCLUSIONS A pharmacologically inert, acellular pertussis-toxoid vaccine that is easily standardized is safe and confers substantial protection against pertussis.

Correlation between Pertussis Toxin IgG Antibodies in Postvaccination Sera and Subsequent Protection against Pertussis

All acellular pertussis vaccines contain pertussis toxoid and induce protection against pertussis. This study investigated the relation between the postvaccination levels of pertussis toxin (PT) serum IgG and protection against pertussis. PT IgG was determined in sera obtained 21-77 days after the third vaccination from 813 children who received 3 doses of pertussis toxoid. The children were followed for 21-33 months after vaccination for the occurrence of pertussis. Of the children, 126 were exposed to pertussis in their households. The median PT IgG concentration was 79 U/mL in those who developed severe pertussis (>/=21 day of paroxysmal cough), 156 U/mL with mild pertussis (<21 days of paroxysmal cough), and 246 U/mL in those who did not develop pertussis (79 vs. 246, P<.0001). Corresponding values in the 687 children with no household exposure were 99, 124, and 155 U/mL, respectively (99 vs. 155, P<.0001). Thus, there is a highly significant correlation between the level of vaccine-induced serum PT IgG and protection against pertussis.

Evidence for a secular trend in menopausal age: a population study of women in Gothenburg

Objective To describe secular trends in age of natural menopause. Design A prospective study based on a random sample of the total female population in Gothenburg, Sweden, started in 1968 with follow-ups in 1974–75, 1980–81, 1992–93, and 2000–02. Participants: 1,462 women born in 1930, 1922, 1918, 1914, and 1908 (participation rate, 90.1%) representative of women of the same ages in the general population. Information regarding menopausal age was provided by 1,373 of the 1,462 women (93.9%). The number was further reduced to 1,017 after exclusion of women who had taken hormones, undergone a surgical menopause, or both. Results The mean age at natural menopause showed a steady increase across birth cohorts. Trends were similar in women who had smoked and women who had never smoked, even after adjusting for different covariates. The upward trend was 0.1 years per birth year (SE 0.020, P < 0.0001). Interestingly, women with earlier menarche had a somewhat earlier age at menopause, independent of the cohort effect. When hormone users were included in the sample, the cohort effect was also found to be independent of oral contraceptive use and hormone therapy. Conclusions This study has shown that, independent of variations in socioeconomic status, smoking status, oral contraceptive use, or hormone therapy use, as well as other potential confounders, there was a highly significant secular trend of increase in menopausal age. The observation of a positive association between menarche and menopausal age has, to our knowledge, not previously been described.

Serum Homocysteine in Relation to Mortality and Morbidity From Coronary Heart Disease A 24-Year Follow-Up of the Population Study of Women in Gothenburg

Background—Elevated serum total homocysteine (tHcy) is an established risk factor for cardiovascular disease (CVD), especially in men. However, there are few prospective population studies on female cohorts, and none of these has been longer than 13 years. Methods and Results—The Population Study of Women in Gothenburg began in 1968/1969, at which time a representative population-based cohort of women aged 38, 46, 50, 54, and 60 years was recruited. The present cohort is a prospective follow-up of 1368 women in the original cohort for whom blood samples were stored and who were free of previous acute myocardial infarction (AMI) at the 1968/1969 baseline. Homocysteine was analyzed in 2001 with frozen serum from the baseline study and related to AMI incidence and mortality during 24 years of follow-up. Cox regression analyses were used with adjustment for age, traditional risk factors, and tHcy modifiers. For the fifth tHcy quintile, relative risk was 1.86 (95% CI 1.06 to 3.26) for AMI and 5.14 (95% CI 2.22 to 11.92) for death due to AMI. Age-standardized Kaplan-Meier plots for the fifth tHcy quintile versus others showed significant differences both for AMI and for death due to AMI that were apparent after 15 years of follow-up. Conclusions—Homocysteine in middle-aged women is an independent risk factor for myocardial infarction and in particular mortality due to myocardial infarction. The study illustrates that long-term prospective studies might be necessary to show effects of homocysteine levels on AMI morbidity and mortality in women.

Performance of the SF-36 Health Survey in screening for depressive and anxiety disorders in an elderly female Swedish population

Objective: To assess the sensitivity, specificity and predictive validity of suggested cut-off scores in the SF-36 mental health (MH) and mental component summary (MCS) in screening for depressive and anxiety disorders in a population sample of older Swedish women. Method: The sample comprised 586 randomly selected females aged 70–84 years who took part in an in-depth psychiatric examination. This provided the ‘gold standard’ against which the usefulness of SF-36 recommended thresholds for screening for depressive and anxiety disorders in older Swedish women was examined. Results: Based on DSM-III-R criteria, 69 women (12) were diagnosed with depression (major depression, dysthymia and/or depression NOS) and 49 (8) with generalised anxiety and panic disorders. The previously recommended MH and MCS cut-offs (i.e. 52 and 42) gave a specificity for diagnosis of depression of 92 and 82 and sensitivity of 58 and 71, respectively. Both the MH and MCS were good predictors of depressive disorders but poor predictors of anxiety disorders. Conclusion: The study supports the predictive validity of suggested SF-36 MH and MCS cut-off scores in screening for depressive disorder but not for anxiety disorder in older women in Sweden.

Trends and prognoses of dental status in the Swedish population: analysis based on interviews in 1975 to 1997 by Statistics Sweden

The aims of this study were to describe changes in dental status over the 22-year period from 1975 to 1997, and to make a prognosis of dental status based on these data for the years 2005 and 2015. The study is based on regular investigations of the living conditions performed by Statistics Sweden of samples varying between 11,582 and 14,964 participants and a response rate from 78% to 86%. The questions of the interview used in this study were focused on dental status and utilization of dental services. The prevalence of edentulism in the age group 25-74 years decreased from 19% in 1975 to 3% in 1996/97. The proportion of dentate persons increased from 75% in 1975 to 97% in 1996/97 in age group 45-64 years with similar trends in the other age groups. In 1996/97, 2.1% of the whole sample (16-84 years) reported that they had received implant-supported restorations. The rate was higher among the elderly and the edentulous subjects. The great regional differences in dental status found in the first part of the observation period remained only in the oldest age group in 1996/97. The prognosis predicts that 95% of the subjects in age group 65-74 years and 90% in age group 75-84 years will be dentate in the year 2015. The substantial increase of dentate subjects among the elderly that has occurred during the past few decades and its expected continuation in the coming years implies a great change in need and demand for dental care services.

Utilization of dental services in relation to socioeconomic and health factors in the middle-aged and elderly Swedish population

The aims of this study were to describe the change in reported time since the latest visit to a dentist between the years 1980/81 and 1988/89 and the reported use of dental services in relation to age, dental state, and socioeconomic and health characteristics in a sample of the Swedish population in 1988/89. The studies are based on interviews by Statistics Sweden about the living conditions. In the investigations in 1980/81, 14,964 inhabitants between 16 and 84 years of age participated, and in 1988/89, 13,309 inhabitants. In all age groups there was a significantly higher frequency of reported visits to a dentist last year in 1988/89 than in 1980/81. In the age group 50-64 years old this figure increased from 54% to 75%, and in the age group 65-84 years old it increased from 26% to 39%. In the investigation in 1988/89 about 75% of the dentulous women in all age groups up to 75 years reported visiting a dentist last year. The relative risk for not visiting a dentist last year, adjusted for age, gender, and dental state, was higher in dentulous subjects with low income and education, not married, not native-born, living in rural areas, smoking, and low social and physical activity. The results of the logistic regression analysis showed that, among the elderly, functional ability and general health factors have lower significance for time since last visit to a dentist than socioeconomic, social support, and life-style factors.

Number of teeth – a predictor of mortality in 70-year-old subjects

OBJECTIVES To investigate whether the number of teeth at age 70 is an independent predictor of mortality. METHODS Within the gerontological population studies in Göteborg, Sweden, four birth cohorts born in 1901/1902, 1906/1907, 1911/1912 and 1922 were examined cross-sectionally at 70 years of age. The total number of participants in the odontological cohorts was 1803. Mortality data were collected from the national Swedish health registers. Cox regression models were used to measure the association between mortality and the number of teeth with adjustment for covariates such as health factors, socio-economic and lifestyle factors. RESULTS The prevalence of edentulism showed a marked change from 51% in the first cohort to 16% in the last cohort. The 7-year mortality rate was 14% in women and 28% in men, and the highest in edentulous men in the last two cohorts (42% and 47% respectively). The 7-year mortality including all four cohorts showed a hazard ratio of 0.96 (95% CI 0.94-0.98; P < 0.001) for the number of teeth with adjustment for cohort. The corresponding 18-year mortality including the three first cohorts showed a hazard ratio of 0.98 for women and 0.97 for men. The number of teeth was an independent statistically significant predictor of 7-year mortality in both genders and of 18-year mortality in men. CONCLUSIONS The result showed that each remaining tooth at age 70 decreased the 7-year mortality risk by 4%. The difference between edentulous subjects and dentate subjects with >or=20 teeth regarding 7-year mortality was significantly higher in the last compared to the first cohort. The number of teeth was a significant predictor of mortality independent of health factors, socio-economic status and lifestyle.

Mass vaccination of children with pertussis toxoid: decreased incidence in both vaccinated and nonvaccinated persons

During 1979-1995, there was no vaccination against pertussis in Sweden. With the aim of studying the epidemiology and transmission of pertussis, mass vaccination with pertussis toxoid of children born during the 1990s was instituted in the Göteborg area (population, 778,597) in 1995. Infants were offered 3 doses of pertussis toxoid combined with diphtheria and tetanus toxoids. Children aged > or =1 year were offered 3 doses of pertussis toxoid alone. From June 1995 through February 1999, 167,810 doses of pertussis toxoid were given to 61,219 children born during the 1990s (56% received 3 doses). The number of Bordetella pertussis isolates per year declined from 1214 (1993-1995) to 64 (January 1997 through June 1999; P<.0001), and hospitalizations due to pertussis declined from 62 to 5 (P<.0001). Significant decreases in B. pertussis isolates and hospitalizations occurred in all age groups, including adults and nonvaccinated infants. Thus, mass vaccination of children with pertussis toxoid decreases spread of B. pertussis in the population.

Waist circumference, body mass index, and risk for stroke in older people: a 15 year longitudinal population study of 70- year-olds.

OBJECTIVES: To investigate waist circumference (WC) and body mass index (BMI) at age 70 as risk factors for stroke.