Individual- and area-level influence on suicide risk: a multilevel longitudinal study of Swedish schoolchildren

BACKGROUND

Characteristics related to the areas where people live have been associated with suicide risk, although these might reflect aggregation into these communities of individuals with mental health or social problems. No studies have examined whether area characteristics during childhood are associated with subsequent suicide, or whether risk associated with individual characteristics varies according to childhood neighbourhood context.

METHOD

We conducted a longitudinal study of 204,323 individuals born in Sweden in 1972 and 1977 with childhood data linked to suicide (n = 314; 0.15%) up to age 26-31 years. Multilevel modelling was used to examine: (i) whether school-, municipality- or county-level characteristics during childhood are associated with later suicide, independently of individual effects, and (ii) whether associations between individual characteristics and suicide vary according to school context (reflecting both peer group and neighbourhood effects).

RESULTS

Associations between suicide and most contextual measures, except for school-level gender composition, were explained by individual characteristics. There was some evidence of cross-level effects of individual- and school-level markers of ethnicity and deprivation on suicide risk, with qualitative interaction patterns. For example, having foreign-born parents increased the risk for individuals raised in areas where they were in a relative minority, but protected against suicide in areas where larger proportions of the population had foreign-born parents.

CONCLUSIONS

Characteristics that define individuals as being different from most people in their local environment as they grow up may increase suicide risk. If robustly replicated, these findings have potentially important implications for understanding the aetiology of suicide and informing social policy.

The role of maternal factors in sibling relationship quality: a multilevel study of multiple dyads per family

BACKGROUND

  Although many children grow up with more than one sibling, we do not yet know if sibling dyads within families show similarities to one another on sibling affection and hostility. In the present study the hypotheses were tested that (a) there will be significant between family variation in change in sibling affection and hostility and (b) this between family variation will be explained by maternal affective climate, operationalized as positive and negative ambient parenting, differential parenting and maternal malaise.

METHODS

  A general population sample of families with single and multiple sibling dyads were visited twice, 2 years apart. Up to 2 children in a family acted as informants; 253 relationships were rated in 118 families. A cross-classified, multilevel model was fit to separate between-family and within-family variance in sibling relationships while simultaneously controlling for informant and partner influences.

RESULTS

  Thirty-seven percent of the variance in change in sibling affection and 32% of the variance in change in sibling hostility was between family variance. The measured maternal affective climate including, maternal malaise and maternal ambient and differential hostility and affection explained between family differences.

CONCLUSIONS

  Sibling relationship quality clusters in families and is partly explained by maternal affective climate.

Impact of patients' socioeconomic status on the distance travelled for hospital admission in the English National Health Service

OBJECTIVES

To compare the distances travelled for inpatient treatment in England between electoral wards prior to the introduction of a policy to extend patient choice and to consider the impact of patients' socio-economic status.

METHODS

Using Hospital Episode Statistics for 2003-04, the distance from a patient's residence to a National Health Service hospital was calculated for each admission. Distances were summed to electoral ward level to give the distribution of distances travelled at ward level. These were analysed to show the distance travelled for different admission types, ages of patient, rural/urban location, and the socioeconomic deprivation of the population of the ward.

RESULTS

There is considerable variation in the distances travelled for hospital admission between electoral wards. Some of this is explained by geographical location: individuals living in more rural areas travel further for elective (median 27.2 versus 15.0 km), emergency (25.3 versus 13.9 km) and maternity (25.0 versus 13.9 km) admissions. But individuals located in highly deprived wards travel less far, and this shorter distance is not explained simply by the closer location of hospitals to these wards.

CONCLUSIONS

Before the introduction of more patient choice, there were considerable differences between individuals in the distances they travelled for hospital care. An increase in patient choice may disproportionately benefit people from less deprived areas.

Prevalence of and risk factors for HIV infection in blood donors and various population subgroups in Ethiopia

The aim was to determine the prevalence of HIV infection and risk factors for HIV infection in various population subgroups in Ethiopia. Serum panels from blood donors (n = 2610), from various population subgroups in Ethiopia were tested for anti-HIV-1/2 by ELISA. All ELISA repeatedly reactive samples were subjected for confirmation by immunoblot (IB) and anti-HIV-1 and anti-HIV-2 specific ELISAs. 155/2610 (5.9%) blood donors were HIV-1 infected. Of pregnant women, 84/797 (10.5%) were HIV-1 infected, and 1/797 (0.1%) was HIV-2 infected. 1/240 (0.4%) individuals from the rural population were HIV-1 infected. 198/480 (41.3%) female attendees, and 106/419 (25.3%) male attendees at sexual transmitted disease (STD) clinics were HIV-1 infected. One (0.2%) male, and 2 (0.4%) female STD patients were infected with both HIV-1 and HIV-2. It was concluded that the prevalence of HIV-1 infection varied from 0.4% among urban residents to 25.3-41.3% among STD attendees. There is a low prevalence of HIV-2 present in Ethiopian subjects. Risky sexual behaviour is significantly associated with HIV-infection in Ethiopia.

A new ultrasensitive assay for quantitation of HIV-1 RNA in plasma

Nucleic acid-based diagnostic assays for the quantitation of plasma HIV-1 RNA levels are used to monitor disease progression and the response of patients to antiretroviral drug therapy. The LCx HIV RNA Quantitative Assay (Abbott Laboratories, North Chicago, IL) is an assay for the quantitation of HIV type 1 RNA in plasma that uses competitive reverse transcription PCR (RT-PCR) followed by Microparticle Enzyme Immunoassay, and includes an internal control for inhibition and RNA recovery, that is taken through the entire sample preparation procedure. The performance of the assay was assessed for 1 and 0.2 ml sample volumes. For a 1 ml sample volume, the lower limit of detection was found to be 50 copies/ml with a linear range from 50 to 1 million copies/ml. For a 0.2 ml sample volume, the lower limit of detection was found to be 178 copies/ml with a linear range from 178 to 5 million copies/ml. The assay is able to detect and quantitate HIV subtypes A-G and group O. LCx HIV RNA assay quantitation results are highly correlated to the standard and ultrasensitive Amplicor HIV-1 Monitor assay (Roche Molecular Systems) quantitation results. Assay performance is consistent with the use of this test for routine quantitation of HIV-1 RNA in plasma.

Diagnosis of Chlamydia trachomatis genitourinary infection in women by ligase chain reaction assay of urine

Genitourinary infection with Chlamydia trachomatis is a common and potentially serious sexually transmitted disease. Diagnosis of C trachomatis infection in women typically relies on culture of endocervical swabs, an invasive and expensive procedure. The ligase chain reaction (LCR) is an in-vitro nucleic acid amplification technique that exponentially amplifies selected DNA sequences. We have compared an LCR-based assay to detect C trachomatis plasmid DNA in first void urine with culture of endocervical swabs for matched specimens from 1937 women from four geographic regions. Discordant specimen pairs were further tested by direct fluorescent antibody staining for elementary bodies and an alternative LCR assay based on the chlamydial outer membrane protein gene. An "expanded gold standard" was defined to include all culture-positive as well as culture-negative, confirmed LCR-positive women. The sensitivity and specificity of the LCR assay with first void urine samples compared with the expanded gold standard were 93.8% and 99.9%, respectively; the corresponding values for culture were 65.0% and 100%, respectively. Thus, an automated LCR assay of readily obtained urine samples showed a detection rate for infected women almost 30% greater than that of endocervical swab culture. The LCR assay was highly effective for the detection of C trachomatis in urine from women with or without signs or symptoms of chlamydial genitourinary tract infection.

Complete nucleotide sequence of HTLV-II isolate NRA: comparison of envelope sequence variation of HTLV-II isolates from U.S. blood donors and U.S. and Italian i.v. drug users

The entire nucleotide sequence of human T-cell lymphotropic virus type II (HTLV-II) from a previously described isolate of patient NRA (HTLV-IINRA) was determined. Clones encoding the 5' LTR and gag, pol, env and tax/rex open reading frames were subcloned and sequenced on both strands. The provirus consisted of 8957 nucleotides and showed 95.2% homology with the HTLV-IIMo prototype at the nucleotide level. Less than 5% amino acid variation between HTLV-IINRA and HTLV-IIMo was observed for coding regions. Although isolate HTLV-IINRA had an additional 25 amino acids at the 3' end of tax/rex, this region was 96% homologous with the 5' end of HTLV-IIMo 3' LTR. To further investigate HTLV-II variability, a portion of the env gp46 gene derived from 9 HTLV-II infected persons was amplified by polymerase chain reaction and sequenced. Sequence was obtained for 320 nucleotides corresponding to HTLV-IIMo positions 5291 to 5610. Isolates similar to the HTLV-IIMo and HTLV-IINRA prototypes were identified, and sequences were highly conserved.

The prevalence of antibody to HTLV-I/II in United States plasma donors and in United States and French hemophiliacs

Antibody to HTLV-I/II was detected in 19 (0.3%) of 6286 plasma donors from five regions of the United States (US). This seroprevalence rate is approximately 10 times that in whole blood donors. The regional distribution of infection was as follows: Southwest, 0.68 percent; Southeast, 0.45 percent; Midwest, 0.28 percent; Northwest, 0.1 percent; and Northeast, 0.0 percent. Rates of HTLV-I/II infection in blacks (0.74%) and Hispanics (0.66%) were higher (both, p less than 0.001) than those in whites (0.08%). All 19 infected units were donated by subjects aged 30 or older, even though 52.9 percent of the donations came from persons less than 30 years old. Equal rates of HTLV-I/II infection were found in men (0.31%) and women (0.29%). No HTLV-I/II antibody was detected in 154 French and 25 US hemophiliacs who were transfused regularly with noninactivated plasma or its derivatives. This suggests that the transfusion of HTLV-I/II-seropositive plasma products does not transmit the viral infection.

Rhinovirus detection using probes from the 5' and 3' end of the genome

This study investigated the abilities of cDNA probes from the 5' and 3' ends of the genome of human rhinoviruses (HRV-) 14, 9, and 1B to detect RNA from 59 rhinovirus serotypes. The results show that probes from the 5' end of the genomes of HRV-14, 9, and 1 B detected a large number of serotypes but the detection rate was variable and depended on the degree of homology with the particular probe. In contrast, all the 3' end probes were specific for the homologous virus. However, a long HRV-9 probe detected a large number of serotypes. It was concluded that such cDNA probes would not detect all serotypes with equal efficiency. Synthetic oligonucleotides corresponding to short but highly conserved regions in the 5' non coding region may overcome this problem.