Preface

This Detailed Tables Report (Summary Tables) is a collection of tables generated using data collected in the 1999 and 2000 National Household Surveys on Drug Abuse (NHSDA).   See the Table of Contents (TOC) .  The majority of these tables are trend tables presenting estimates from the 1999 and 2000 NHSDA surveys. Select tables present only estimates from the 2000 NHSDA (if the same or comparable data are not available from the 1999 NHSDA). In addition, a select number of tables contain annual averages, which are generated by combining the 1999 and 2000 data (if there are not sufficient data within a single year to produce reliable estimates).

During the processing of the 2000 NHSDA data, an error was discovered in the computer programs that assigned imputed values for recency of use, frequency of use, and age at first use of several drugs on the 1999 data file. In preparing the 2000 Summary of Findings report and the Detailed Tables, 1999 data were revised to correct for this error. Thus, many of the 1999 estimates shown in the Detailed Tables are different from those released earlier. Estimates of lifetime use of substances were unaffected, but estimates of past year and past month use were all revised. In most cases the updated numbers are nearly identical. The effects are noticeable for only four of the substances (alcohol, marijuana, inhalants, and heroin), in addition to the composite measures "any illicit drug" and "any illicit drug other than marijuana." For these substances, all of the revised estimates were lower than the previously reported ones. For inhalants, the estimates are considerably lower. More detail concerning the 1999 imputation error, how the error was discovered, and the corrective actions that were taken can be found in Appendix B of the Summary of Findings report.

Table Numbering

The tables within this document are numbered using a three part numbering scheme, e.g., 1.15A. The first part of the table number (1.15A) is the subject matter section to which a particular table belongs. The second part (1.15A) is the actual number of a table within a particular section. The third part (1.15A) is a table type indicator, an alphabetic letter appended to the table number. There are multiple table types for each table number.

The subject matter sections and the number of tables per section are as follows:

Section 1: Illicit Drug Use Tables:  1.1 to 1.110

Section 2: Tobacco and Alcohol Use Tables:   2.1 to 2.111

Section 3: Risk and Protective Factor Tables:   3.1 to 3.48

Section 4: Incidence Tables:   4.1 to 4.18

Section 5: Dependence, Abuse and Treatment Tables:  5.1 to 5.66

Section 6: Miscellaneous Tables:   6.1 to 6.85

Section 7: Sample Size and Population Tables:  7.1 to 7.16

The table type indicators are defined below:

The majority of tables within the Detailed Tables contain 5 table types (A, B, C, D, and P) as defined above. Note that table type N is used exclusively within Section 7 to display the sample size counts. Exceptions to this organization are noted below:

• Section 4 (Incidence Tables) contains only table types A and C - Table type A contains numbers of initiates, mean age, and age specific rates. Table type C contains the associated standard errors for each of these types of estimates.

• Section 7 (Sample Size Tables) contains only table types A, C, and N - Population counts, standard errors, and sample sizes are displayed in table types A, C, and N, respectively. Percentages of the population and associated standard error tables are not provided in this section.

• Selected table sets within Section 1 (Illicit Drug Use Tables), Section 2 (Tobacco and Alcohol Use Tables), Section 5 (Dependence, Abuse, and Treatment Tables, and Section 6 (Miscellaneous Tables) include only table types A, B, C, and D. Selected tables within these sections either present estimates for the 2000 NHSDA only, or contain annual average estimates for 1999 and 2000 NHSDA data combined. In both cases these select tables are not trend tables; thus, significance tests between 1999 and 2000 estimates are not relevant, and table type P is not applicable.

Table Organization

The Detailed Tables is organized by table type into two overall groups as follows:

Prevalence Estimates and Sample Sizes - Table Types A, B, and N (If Applicable)

Standard Errors and P-Values - Table Types C, D, and P (If Applicable)

Within each of these overall groups of tables, both a table index and a list of tables are provided for each of the sections defined above. Table number indexes summarize the information contained in each table in a tabular form. Key variables used in these index tables are defined in the Key to Selected Variables. Due to space restrictions, neither the section indicator nor the table type indicator components of the table numbers are used in the index. Proper use of the indexes depends on careful examination of the information included in the titles of the tables.

Within each individual table in the prevalence estimates and sample sizes group, a link has been provided to the list of tables for the standard errors and p-values group of tables. Conversely, for each individual table in the standard errors and p-values group, a link has been provided to the list of tables for the prevalence estimates and sample sizes group of tables. These links are located at the end of the table title for each table and provide minimal linkage between the two overall groups of tables. Note that the links on the titles will only direct the user to the list of tables, not the table indexes.

Locating a Table

A list of tables and a table index have been provided for each subject matter section to assist users in locating a specific table of interest within this set of Summary Tables. A specific table can be located by using the list of tables for one of the subject matter sections. For example, if the user is interested in information about the prevalence of past month illicit drug use among youth aged 12 to 17, the user would review the list of tables for prevalence estimates in Section 1: Illicit Drug Use Tables and select Table 1.2B, which will move the user directly to Table 1.2B. For the associated standard error or p-value table, the user would choose the list of table link located at the end of the table title. This link will move the user to the list of tables for the subject matter sections, from which the user can choose the subject matter of interest and then the associated standard error or p-value table of interest. The table indexes are provided as a tool, which categorize the information contained in each table in tabular form. The table indexes can be used to determine tables categorized by content area, age groupings, racial/ethnic characteristics, demographic, and geographic characteristics. However, within the table index, links to the corresponding tables are not available.