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D G Fisher

Publications and source records attributed to D G Fisher.

At least 19 recordsLinked to original sources
PubMed2005

Modeling censored-in-the-middle condom use data.

Many HIV prevention programs seek to reduce the risk of infection through increases in condom use. Condom use is often expressed as a proportion: the number of sexual contacts in which a condom is used divided by the total number of sexual contacts. The distribution of this proportion has several undesirable characteristics-the principal one is bimodality. Bimodality results from excessive numbers of 0% and 100% responses, creating distributions that are censored-in-the-middle. The purpose of this paper is to show how censored condom use data can be usefully modeled using Tobit regression. Tobit regression first transforms observed variable scores into latent variable scores, scores on an unobserved, hypothetical condom use variable, and then the latent variable scores are modeled using one or more explanatory variables. Data from the National Institute on Drug Abuse Cooperative Agreement for HIV/AIDS Community-Based Outreach/Intervention Research program for frequency of condom use and number of drug injecting sex partners were used to illustrate the method. We found that for every additional drug injecting sex partner, the probability of using condoms decreased by approximately 1%.

Condoms↗
PubMed2000

Telephone survey of Alaskan pharmacists' nonprescription needle-selling practices.

OBJECTIVES: To determine the availability of nonprescription needles and syringes (NS) through pharmacy sales and to assess the impact of pharmacy policies and municipal paraphernalia laws on pharmacists' selling practices. DESIGN: Telephone survey of all pharmacies in Alaska's four largest cities. SETTING: Anchorage, Fairbanks, Juneau, and Ketchikan, Alaska. SUBJECTS: A single pharmacist from each pharmacy represented in the cities' phone books. MAIN OUTCOME MEASURES: Reports of (1) pharmacies' policies and individual pharmacists' procedures regarding the nonprescription sale of NS, (2) pharmacists' selling practices, and (3) identification of conditions that may affect pharmacists' decisions to sell nonprescription NS. RESULTS: Response rate of 86% (37/43); 77% of pharmacists reported selling at least one nonprescription NS in the last month. Store policy was related to selling practices; however, there was no difference in selling practices between a city with a paraphernalia law and cities without such laws. Logistic regression revealed pharmacists were more likely to sell NS if they worked in chain pharmacies and estimated that a high number of other local pharmacists sell nonprescription NS. CONCLUSION: NS are available through nonprescription sales in Alaskan pharmacies. The majority of pharmacies have store policies that permit pharmacists to sell nonprescription NS, either in all cases or at their discretion. Municipal paraphernalia laws do not determine the selling practices of individual pharmacists.

Alaska↗
PubMed2000

Etiology of limited transmission diseases among drug users: does recent migration magnify the risk of sharing injection equipment?

Epidemiological studies have attributed area-specific changes in infectious disease prevalence to human migration. There is a paucity of research investigating the postmigration adjustment period as an effect on risk behaviors that are required in limited transmission diseases. A two-group typology, derived by cluster analysis, allowed for an analytical differentiation in the postmigration period. The cluster variable and other possible cofactors were included in linear and logistic regression modeling of sharing drug injection equipment among drug users in Alaska. The results indicate that among participants who have injected drugs, those in the postmigration adjustment period are nearly six times more likely to share injection equipment than those drug users who are not in a postmigration period. Further research is suggested and limitations are discussed.

Alaska↗
PubMed2000

Unemployment, drug use, and HIV risk among American Indian and Alaska Native drug users.

American Indians and Alaska Natives have had low employment in recent history. Drug users also have low employment due to cycles of drug use and relapse,and the impact of the type of drug abused on levels of functioning. Drug use is associated with increased HIV risk through injection drug use, frequency of injection, and needle sharing. Data from three sites of the NIDA Cooperative Agreement for Community Based-Outreach/Intervention Research were analyzed to determine the relationship among race/ethnicity, age, and level of educational attainment on employment and unemployment at intake interview and six-month follow-up. HIV risk for those employed and unemployed was then assessed. American Indian and Alaska Native drug users were younger, less educated, and less likely to have a paid job at both intake and follow-up than non-Native drug users. Those participants who were unemployed at baseline interview who were American Indian/Alaska Native were less likely to transition to employment at six-month follow-up than other race/ethnicity groups in the cohort. However, all participants showed low levels of employment at follow-up. Individuals who were employed at baseline and those who transitioned to employment had lower levels of injection drug use and needle sharing than those who were unemployed at both baseline and follow-up. American Indian and Alaska Native drug users may be at risk for acquisition of HIV due to drug risk behaviors that appear to be associated with unemployment.

Adult↗
PubMed2000

Alaska Native drug users and sexually transmitted disease: results of a five-year study.

Although Alaska has one of the highest rates of alcohol consumption in the U.S., there are very few reports of other drug use in Alaska. This five-year NIDA-funded study sampled out-of-treatment injection drug users (IDUs) and crack cocaine smokers in Anchorage, Alaska. This paper is a summary of results comparing risk behavior for HIV and sexually transmitted disease infection among Alaska Natives (n=216) to non-Natives (primarily Blacks n=394 and Whites n=479) from this study. IDUs and crack cocaine smokers were recruited using a targeted sampling plan. All subjects tested positive to cocaine metabolites, or morphine, using urinalysis, or had visible track marks. Several analyses of this database have indicated that Alaska Native women are at high risk for gonorrhea infection. They are also at risk for HIV infection due to high rates of behavior related to blood-borne disease transmission. We have also found that White men who have sex with both White and Alaska Native women are significantly less likely to use condoms with the Alaska Native women. HIV preventive education efforts aimed at Alaska Native women need to be implemented on a major scale.

Alaska↗
PubMed1998

Sex partners of Native American drug users.

This study describes patterns of sexual behavior and condom use in a sample of Native American drug-using men and women (N = 114). Data are self-reports of sexual behavior in the last 30 days, including descriptions of the most recent sex partners up to five. These data provided information on 157 sex partner pairs, of which at least one partner was a drug user. Native American women (55%) were more likely than Native American men (23%) to report never using condoms for vaginal and anal sex in the last 30 days. Compared with other ethnic pair combinations, sex partner pairs composed of Native American women and white men (n = 18) were the least likely to use condoms (6% of pairs) and the most likely to report an injection drug user (IDU) sex partner (33% of pairs). These results suggest a potential vector of HIV and other sexually transmitted disease (STD) transmission between white male IDUs and Native American women and highlight the need for further qualitative and quantitative research to examine the factors underlying this pattern of sexual risk behavior.

Adult↗
PubMed1998

High-risk sexual behavior among drug users. The utility of a typology of alcohol variables.

OBJECTIVES: The purpose of this study was to develop a typology of drug users based on alcohol use variables and then determine the utility of this typology for predicting high-risk sexual behavior, controlling for the personality traits of sensation seeking and risk proneness. METHODS: A sample of 283 out-of-treatment drug users in Anchorage, Alaska, were interviewed regarding their alcohol and drug use, sexual behavior, sensation seeking, and risk proneness. The sample was 66% male; 44% white, 26% black, and 24% Native American; had a median age of 36 years; and a median monthly income of $500 to $999. RESULTS: Cluster analyses of alcohol variables showed the presence of two clusters, one of which is characterized by relatively high alcohol consumption and early age of first alcohol use. This alcohol typology was significantly related to several sexual risk behaviors, including having sex with multiple partners without consistent condom use (chi 2(1) = 10.47, p < .01), having sex with an injection drug user (IDU) without consistent condom use (chi 2(1) = 4.87, p < .05), number of sex partners (t(281) = -2.16, p < .05), STD history (chi 2(1) = 7.86, p < .01), and having traded sex for drugs or money recently (chi 2(1) = 6.91, p < .01) or in one's lifetime (chi 2(1) = 9.20, p < .01). All but one of these associations remained significant after controlling for sensation seeking and risk proneness. CONCLUSIONS: Among this sample of out-of-treatment drug users, a typology based on patterns of alcohol use was found to be associated with several measures of high-risk sexual behavior. Drug users who were classified as high risk on the basis of their lifetime and current alcohol use patterns were found to be significantly more likely than low-risk drug users to have engaged in risky sexual behavior. Risk proneness does not appear to account for this pattern of associations.

Adult↗
PubMed1998

Hepatitis C virus and depression in drug users.

OBJECTIVES: Clinical case studies have implicated depression as a possible side-effect of interferon treatment for the Hepatitis C virus (HCV). However, because these studies generally did not include a pretreatment assessment of depression, it cannot be definitively stated whether depression is a side-effect of interferon treatment, a syndrome coexisting with HCV, or a common characteristic of individuals who are vulnerable to HCV infection. To gather more information about this issue, self-reported depressive symptomatology of drug users with HCV who have not received interferon treatment was compared to that of uninfected drug users. METHODS: Subjects were 309 drug users not currently in substance abuse treatment who were participating in a National Institute on Drug Abuse project. Subjects completed the Center for Epidemiological Studies-Depression (CES-D) instrument and provided a blood sample for HCV testing. RESULTS: Serological findings revealed that 52.4% of the subjects tested positive for HCV antibodies. Of the HCV-positive subjects, 57.2% had significant depressive symptomatology, whereas only 48.2% of the HCV-negative subjects did, for an overall rate of 52.6%. The two groups also differed on two specific dimensions of depression, with the HCV-positive group scoring lower on the Positive Affect scale and higher on the Somatic/Retarded Activity scale. CONCLUSIONS: These findings reveal high levels of depressive symptomatology among drug users, as well as the possibility of a coexisting depressive syndrome with HCV infection. These findings raise the possibility that depression associated with interferon treatment may, at least partially, be accounted for by preexisting depression. Further research is needed to determine the nature and origins of depression in individuals in treatment with interferon for HCV with specific focus placed on determining the dimensions of depression associated with HCV infection and interferon treatment.

Adolescent↗
PubMed1998

Sex partners of Alaskan drug users: HIV transmission between white men and Alaska Native women.

This study describes patterns of sexual behavior and condom use in a sample of 1125 Black, White, and Alaska Native drug users. Data are self-reports of recent sexual behavior, including descriptions of (up to) the five most recent sex partners. This provided information on 1116 sex partner pairs, of which at least one partner was a drug user. Sex partner pairs involving a White man and an Alaska Native woman were frequently reported. Level of condom use within these pairs was significantly lower than within all other pairs. The implications of a potential vector of HIV transmission from White, drug using men to Alaska Native women are discussed.

Adult↗
PubMed1998

A cluster analysis of not-in-treatment drug users at risk for HIV infection.

The purpose of the analysis described here was to classify not-in-treatment drug users participating in the National Institute on Drug Abuse (NIDA)-sponsored Cooperative Agreement study into several "homogeneous" HIV risk groups using cluster analysis. Data for this analysis (N=17,778) were collected at 19 study sites in the United States and Puerto Rico. Measures selected for the cluster analysis were limited to (a) current drug use and HIV risk behaviors, (b) mutually exclusive behaviors, (c) behaviors directly related to HIV risk, and (d) behaviors that were not statistically rare. Eight homogeneous HIV risk clusters were produced. Crack cocaine use was the most distinguishing feature of three clusters. Another three clusters were distinguishable by drug injection and needle use practices. Two additional clusters could not be grouped with either the crack- or the injection-dominant clusters. Prostitution was the most distinguishing risk behavior of one of these clusters, and extremely high drug injection frequencies and relative rates of risky needle use characterized the other. Composition of the clusters varied significantly by gender, race/ethnicity, educational attainment, and drug use characteristics. In addition, perceptions and behaviors initiated to reduce the chances of becoming infected with HIV varied by cluster. Subjects in the crack-predominant clusters reported low perceptions of the chances of getting AIDS. Perceptions of the chances of becoming infected with HIV among subjects in the injection-predominant clusters were strongly related to injection frequency. Seroprevalence was also related to cluster. Higher rates of HIV infection were evident among the injection-predominant clusters, and higher rates were related to frequency of injection and the rate of risky needle use. Among the crack-predominant clusters, the relationship between drug use and sexual behaviors and HIV infection was less clear.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Gonorrhea among drug users: an Alaskan versus a national sample.

The study described here investigates the replicability of gender-specific risk profiles for gonorrhea based on an Alaskan sample compared to a U.S. national sample of drug users at risk for HIV infection. The Alaska sample (interviewed at a field station in Anchorage, Alaska; N=1,049) and the national sample (interviewed at 18 sites other than Alaska; N=17,619) consisted of cocaine smokers and injection drug users not in drug treatment. A history of gonorrhea infection was self-reported and coded as ever or never. The Anchorage and national risk profile for men included the following factors: (a) history of intranasal or parenteral cocaine use, (b) being black versus nonblack, (c) being older, (d) income from illegal activity, and (e) history of amphetamine use. The Anchorage and national risk profiles for women included the following factors: (a) trading sex for money, (b) being Native American versus non-Native American, and (c) trading sex for drugs. The Anchorage model for women included perceived homelessness as a factor, but it was not retained in the national model. The extent of the replicability of these models illustrates the generalizability of Alaskan findings to other U.S. drug-using populations. The authors also discuss the implications of these findings for disease prevention.

Comorbidity↗
PubMed1998

Pneumococcal carriage in an Alaskan drug-using population.

This study examined the prevalence of pneumococcal carriage rates in an Alaskan drug-using population. Data collection included: (a) The Risk Behavior Assessment, (b) a supplemental smoking questionnaire, and (c) collection and culture of nasal/oropharyngeal specimens for isolation of Streptococcus pneumoniae. The overall carriage rate for S. pneumoniae was 13%. Of seven smoking variables, only hashish smoking within the prior six-month period was significantly associated with pneumococcal carriage. Other carriage indicators in the literature were nonsignificant. Results of the logistic regression indicate that the risk factors for carriage were (a) smoking hashish within the last six months, (b) receiving income from public assistance, and (c) receiving income from a family member or friend.

Adolescent↗