Breast-feeding and a subsequent diagnosis of measles.

BACKGROUND: Breast-feeding protects against many infectious diseases and may also influence immunization outcomes. AIM: This study investigated if breast-feeding protects against clinical measles and if it modified the effect of immunization. METHODS: We used logistic regression with data for 10 207 individuals from the 1970 British Cohort study (BCS70). Breast-feeding data were collected at five years of age, and information on clinical measles infection, as well as socio-economic measures was collected at the age of ten years. Breast feeding was categorized as: breast-fed <1 month (n = 1611), breast-fed for 1-3 months (n = 1016), breast-fed for more than three months (n = 1108), breast-feeding of uncertain duration (n = 21) and never breast-fed (n = 6451). RESULTS: Breast-feeding for more than three months was negatively associated with a diagnosis of clinical measles infection after adjustment for crowding, social class, measles vaccination, parity and sex with an odds ratio (95% confidence interval) of 0.69 (0.60-0.81) compared with those who never breast-fed. Measles vaccination was highly associated with low risk for measles with: 0.14 (0.13-0.16). Age at acute measles infection was not associated with breastfeeding. Breast-feeding did not notably alter measles immunization efficacy. CONCLUSION: Immunization against measles provides effective protection against the disease. A more modest reduction in the risk of a measles diagnosis is associated with breast-feeding. The associations with a diagnosis of measles for breast-feeding and measles immunization are independent of each other.

Decrease of RA-related orthopaedic surgery of the upper limbs between 1998 and 2004: data from 54,579 Swedish RA inpatients.

OBJECTIVES: To describe the overall use and temporal trends in orthopaedic upper limb surgery associated with RA on a nation wide basis in Sweden between 1998 and 2004. METHODS: Data for all inpatient visits during 1998-2004 for patients older than 18 yrs with RA-related diagnoses were extracted from the Swedish National Hospital Discharge Registry (SNHDR). The SNHDR prospectively collects data on all hospital admissions in Sweden according to the International Classification of Diseases (ICD). Data were analysed with respect to orthopaedic surgery of the hand, elbow and shoulder. RESULTS: During the study period, 54,579 individual RA patients were admitted to a Swedish hospital and 9% of these underwent RA-related surgery of the upper limbs. The RA patient cohort underwent a total of 8251 RA-related upper limb surgical procedures. The hand (77%) was most frequently operated on, followed by the shoulder (13%) and the elbow (10%). There was a statistically significant decrease of 31% for all admissions associated with RA-related upper limb surgery during 1998-2004 (P = 0.001). Some 10% of all RA-related upper limb surgery was due to total joint arthroplasties (TJAs), mostly for the elbow (59%). During 1998-2004, all TJAs, elbow-TJAs and shoulder-TJAs had a stable occurrence. In contrast, the overall numbers of hand-TJAs significantly increased (P = 0.009). CONCLUSIONS: Rates of RA-related upper limb surgery decreased and TJAs had a stable occurrence in Sweden during 1998-2004. The findings of this study may reflect trends in disease management and health outcomes of RA patients in Sweden.

Protection against clinical pertussis induced by whole-cell pertussis vaccination is related to primo-immunisation intervals.

AIMS: Information on subjects who had at least three immunisations against pertussis was provided by longitudinal data from the 1970 British Cohort Study (BCS70) and used to assess whether three whole-cell pertussis (wP) immunisations given within less than 5 months confer less effective protection in childhood compared with a schedule with a longer interval. METHODS: Age at pertussis infection was the dependent variable in a Cox regression analysis, to investigate associations with duration between first and third pertussis immunisation; with third immunisation modelled as a time-dependent covariate. Adjustment was for number of pertussis immunisations (three or four), sex, social class and other potential confounding factors. RESULTS: A total of 8545 children were included in the analysis and 556 had a history of whooping cough. A duration of over 4 months between first and third pertussis immunisations is statistically significantly associated with a reduced risk of pertussis infection by age 10 years, compared with three immunisations given over a shorter period, producing a statistically significant adjusted hazard ratio of 0.74 (0.62-0.92). A fourth immunisation against pertussis further enhanced the protective effect with a hazard ratio of 0.59 (0.44-0.82). CONCLUSION: These results were based on a historical UK cohort using wP vaccine, and indicate that a vaccination schedule with an interval between the immunisations greater than 4 months, and also including a fourth immunisation, would be more effective in this population than a three dose schedule within a shorter interval without booster.

Breast feeding and resilience against psychosocial stress.

BACKGROUND: Some early life exposures may result in a well controlled stress response, which can reduce stress related anxiety. Breast feeding may be a marker of some relevant exposures. AIMS: To assess whether breast feeding is associated with modification of the relation between parental divorce and anxiety. METHODS: Observational study using longitudinal birth cohort data. Linear regression was used to assess whether breast feeding modifies the association of parental divorce/separation with anxiety using stratification and interaction testing. Data were obtained from the 1970 British Cohort Study, which is following the lives of those born in one week in 1970 and living in Great Britain. This study uses information collected at birth and at ages 5 and 10 years for 8958 subjects. Class teachers answered a question on anxiety among 10 year olds using an analogue scale (range 0-50) that was log transformed to minimise skewness. RESULTS: Among 5672 non-breast fed subjects, parental divorce/separation was associated with a statistically significantly raised risk of anxiety, with a regression coefficient (95% CI) of 9.4 (6.1 to 12.8). Among the breast fed group this association was much lower: 2.2 (-2.6 to 7.0). Interaction testing confirmed statistically significant effect modification by breast feeding, independent of simultaneous adjustment for multiple potential confounding factors, producing an interaction coefficient of -7.0 (-12.8 to -1.2), indicating a 7% reduction in anxiety after adjustment. CONCLUSIONS: Breast feeding is associated with resilience against the psychosocial stress linked with parental divorce/separation. This could be because breast feeding is a marker of exposures related to maternal characteristics and parent-child interaction.

Orthopaedic surgery of the lower limbs in 49,802 rheumatoid arthritis patients: results from the Swedish National Inpatient Registry during 1987 to 2001.

OBJECTIVES: To analyse changes in the rates of hospital admission and use of orthopaedic surgery to the lower limbs in Swedish patients with rheumatoid arthritis between 1987 and 2001. METHODS: Data for all rheumatoid patients admitted to hospital between 1987 and 2001 were abstracted from the Swedish National Hospital Discharge Register (SNHDR). The data in the register are collected prospectively, recording all inpatient admissions throughout Sweden. The SNHDR uses the codes for diagnoses at discharge and surgical procedures according to the Swedish version of the International Classification of Diseases (ICD). RESULTS: In all, 49,802 individual patients with rheumatoid arthritis were identified, accounting for 159,888 inpatient visits. Hospital admissions for rheumatoid arthritis decreased by 42% (p<0.001) during the period 1987 to 2001. Twelve per cent of all admissions were for a rheumatoid arthritis related surgical procedure to the lower limbs; those admissions decreased markedly (by 16%) between 1987 and 1996, and by 12% between 1997 and 2001, as did the overall number of rheumatoid arthritis related surgical procedures to the lower limbs during both time periods. Between 1997 and 2001, 47% of all rheumatoid arthritis related surgical procedures were total joint arthroplasties. There was an overall trend towards reduced length of hospital stay after orthopaedic surgery to the lower limbs during the study period. CONCLUSIONS: Rates of hospital admission and rheumatoid arthritis related surgical procedures to the lower limbs in Swedish patients with rheumatoid arthritis decreased between 1987 and 2001. This may reflect trends in disease severity, management, and health outcomes of this disease in Sweden.

Trends in disease modifying antirheumatic drug prescription in early rheumatoid arthritis are influenced more by hospital setting than patient or disease characteristics.

OBJECTIVE: To characterise temporal trends and factors associated with the prescription of disease modifying antirheumatic drugs (DMARDs) at the initial consultation in early rheumatoid arthritis (RA). METHODS: Data from 2584 patients with early RA at 19 hospitals were extracted from the Swedish Rheumatoid Arthritis Register for the period 1997-2001. Disease characteristics and DMARD prescription at first consultation with the rheumatologist were investigated using cross tabulation and logistic regression. RESULTS: DMARD prescriptions, particularly for methotrexate, increased from 1997 to 2001 independently of patient characteristics. Stratification by hospital type showed that patients in district hospitals were less likely to be prescribed DMARDs than those in university hospitals (adjusted odds ratio (OR) = 0.53 (95% confidence interval (CI) 0.40 to 0.69), p<0.001), independently of confounding factors. Association of the DAS28 with the likelihood of DMARD prescription was greater among patients attending district hospitals (OR = 1.65 (1.34 to 2.02), p<0.001) than those at university hospitals (OR = 1.23 (1.07 to 1.41), p = 0.003) and county hospitals (OR = 1.34 (1.01 to 1.63), p = 0.003). Interaction testing indicated that the difference was significant (p = 0.007). CONCLUSIONS: Temporal trends in DMARD prescription indicate an increasingly aggressive approach to disease management among Swedish rheumatologists. However, the association of hospital type with DMARD prescription suggests that the adoption of research findings in clinical care varies considerably.

Pre-pubertal growth and cognitive function.

British longitudinal data were used to investigate the association of heights at 22 months and 5 years with a digit recall test at age 10 years. Greater height, particularly at 5 years, was associated with higher scores, suggesting that some exposures influence both growth and capability for cognitive function.

Prevalence of gastrointestinal diseases in two British national birth cohorts.

BACKGROUND: Few studies have investigated the prevalence of multiple gastrointestinal diseases in the general British population. AIM: To examine the prevalence of Crohn's disease (CD), ulcerative colitis (UC), irritable bowel syndrome (IBS), gall stones (GS), and peptic ulcer disease (PUD). SUBJECTS: The 1970 British Cohort Study (BCS70) and the National Child Development Study (NCDS) are two one week national birth cohorts born in 1970 and 1958, respectively. All cohort members living in Great Britain were interviewed in 1999/2000. METHODS: The prevalence rates of the five diseases were calculated, and associations with sex and childhood social class were investigated using logistic regression. RESULTS: At age 30 years, the prevalence rates per 10,000 (95% confidence interval (CI)) in the 1970 and 1958 cohorts, respectively, were: CD 38 (26-49), 21 (13-30); UC 30 (20-41), 27 (18-37); IBS 826 (775-877), 290 (267-330); GS 88 (71-106), 78 (62-94); and PUD 244 (214-273), 229 (201-256). There was a significantly higher proportion with CD (p=0.023) and IBS (p=0.000) in the 1970 cohort compared with the 1958 cohort at age 30 years. Comparing the cohorts in the 1999/2000 sweep, UC, GS, and PUD were significantly (p=0.001, p=0.000, p=0.000) more common in the 1958 cohort. There was a statistically significant trend for a higher risk of GS with lower social class in both cohorts combined (p=0.027). CONCLUSION: The study indicates an increasing temporal trend in the prevalence of CD and suggests a period effect in IBS, possibly due to adult life exposures or variation in recognition and diagnosis of IBS.

Childhood indicators of susceptibility to subsequent cervical cancer.

Common warts could indicate cervical cancer susceptibility, as both are caused by human papillomavirus (HPV). Eczema was also investigated, as atopic eczema has been negatively associated with warts, but non-atopic eczema may be associated with compromised host defences, as observed in patients with HIV, suggesting increased susceptibility to HPV infection and cervical cancer. 'Cervical cancer' was self-reported during an interview by 87 of 7594 women members of two longitudinal British birth cohorts. The accuracy of the diagnoses is limited by lack of confirmation using medical records. Odds ratios are adjusted for common warts and eczema in childhood; and cigarette smoking, number of cohabiting partners and social class in early adult life. The odds ratios of warts and eczema with cervical cancer are 2.50 (95% confidence interval 1.14-5.47) and 3.27 (1.95-5.49), respectively. The association of eczema with cervical cancer is independent of hay fever as a marker of atopy, suggesting the importance of non-atopic eczema. Both heavier smoking compared with non-smoking and four or more cohabiting partners compared with one/none have odds ratios for cervical cancer of 8.26 (4.25-15.10) and 4.89 (1.39-17.18), respectively. Common warts in childhood may indicate cervical cancer susceptibility; this and the relationship with eczema deserves investigation.

Pertussis infection in childhood and subsequent type 1 diabetes mellitus.

AIMS: Pertussis has been implicated but not proven as a risk for Type 1 diabetes mellitus (DM). Previous studies have investigated paediatric, but not adult-onset Type 1 DM. We investigated association of pertussis exposures and Type 1 DM with follow-up into adulthood. METHODS: Longitudinal analysis of 16 820 members (100 with Type 1 DM) of two nationally representative British birth cohorts (the 1970 British Cohort Study (BCS70) and the National Child Development Study (NCDS)) followed from birth to ages 30 years (BCS70) and 42 years (NCDS). Cox regression analysis with age of onset for Type 1 DM as the dependent variable investigated relationships with pertussis infection and immunization, modelled as time-dependent co-variates. Simultaneous adjustment was made for Wild measles, mumps and chickenpox infections; tetanus and smallpox immunizations; sex, parental social class and cohort. The potential confounding factors were modelled as fixed co-variates. RESULTS: Cox regression analysis produced adjusted odds ratios (ORs) (with 95% confidence intervals (CIs)) of 2.21 (1.35-3.59) and 0.73 (0.49-1.05) for Type 1 DM (with onset at any age) associated with pertussis infections and immunization (trend over number of vaccinations), respectively. Adjusted ORs from Cox regression for Type 1 DM with onset after age 10 years are 2.59 (1.56-4.30) for pertussis infection and 0.63 (0.42-0.94) for pertussis immunization. None of the other infections or immunizations are notably associated with Type 1 DM. CONCLUSIONS: Some pertussis infections may be a risk for Type 1 DM and immunization may confer protection. Further research should consider delayed Type 1 DM following pertussis exposures.