Welcome to HDAS - Healthcare Databases Advanced Search
The Healthcare Databases Advanced Search (HDAS) enables you to search across 1 databases
Healthcare Databases Advanced Search enables you to search only Pubmed as a non-logged in user.
A series of help videos have been created to give you a quick introduction to the new functionality in HDAS. These can be accessed here
Frequently Asked Question
How do I use HDAS?
HDAS is designed so that you can build up your search strategy one line at a time. You can construct a search by entering each of your search terms in the search box and hitting search.
How do I get the best results?
Although you can search multiple databases at the same time, if you are doing a literature search, you will retrieve the best results by searching one database at a time. You can then repeat the search in another database. Searching in one database at a time means that you can use the database’s thesaurus and all its available fields and limits.
How do I choose the field I want to search in?
Using HDAS allows you to specify which fields are searched when you run your search. The list of fields varies by provider. The most common fields are immediately available, but a full list of fields can be accessed by selecting the ‘More’ option. This will provide a complete list of fields which can be filtered to help you find the field you want straight away.
Each field has a two-letter code associated with it. If you know the code for the field you want to use then you can enter this directly into the search box, without needing to select it in the interface. The syntax to do this remains unchanged. After your query use a full stop followed by the two letter code. For instance (cancer).ti
For additional field codes use commas to separate each value. i.e. (cancer).ti,ab
How do I search for a phrase?
To search for a phrase, put speech marks around the search term (e.g. "cognitive behaviour therapy"). This will search for results where each word you’ve entered appear together in the order specified.
What happens if I put multiple terms in the search box?
If you search for multiple words, then HDAS will send these to the relevant database provider without modification. this means that the terms will be interpreted according to the rules of each provider.
The three database providers which HDAS calls, use the following rules:
- ProQuest (Medline, Psycinfo, BNI) - AND queries. (cancer cells).ti,ab is the same as (cancer AND cells).ti,ab
- OVID (Embase, AMED, HMIC) - treat terms as phrases. (cancer cells).ti,ab is the same as ("cancer cells").ti,ab
- EBSCO (CINAHL, HBE) - treat terms with ordered adjacency. (cancer cells).ti,ab is the same as (cancer OADJ0 cells).ti,ab
Can I use AND/OR in the search box?
You can also use the operators AND/OR. This allows you to begin building searches more quickly. For instance “cancer AND chemotherapy”. You do not need to use upper case letters.
If you want to search for any of a number of search terms, you should use OR. You must include it between each search term. For instance cancer OR chemotherapy OR radiotherapy
What other operators can I use?
HDAS recognises the following operators:
- ADJn (where n is a number)
- OADJn (where n is a number)
If you want to exclude search terms, you can use NOT. Using this operator between two terms means that you will retrieve results which include the first term but not the second.
How do I use the NOT operator?
Due to the way the NOT operator works, this must be entered into the search box, there is no option to choose NOT from the on screen display. NOT can be used with either terms or row references. These cannot be mixed however. For instance, the following are valid uses of the operator:
- (cancer NOT cells).ti,ab
- 1 NOT 2 (where rows 1 and 2 exist in the strategy)
However, search row references and free text cannot be mixed
- (cancer NOT 1).ti,ab
Using ADJ will return results where the two terms appear in the order specified in the search. ADJn will return results in any order so long as the terms are sufficiently close to one another. For example:
|cancer ADJ cells||Returns results where the selected terms are within one word of one another in the specified order i.e. "cancer cells" but not "cells cancer"|
|cancer ADJ1 cells||Returns results where the selected terms are within one word of one another in any order i.e. "cancer cells" and "cells cancer"|
|cancer ADJ2 cells||Returns results where the selected terms are within two words of one another in any order i.e. "cells [term] cancer" and "cancer [term] cells"|
|cancer OADJ2 cells||Returns results where the selected terms are within two words of one another in the specified order i.e "cancer [term] cells" but not "cells [term] cancer"|
How does ProQuest interpret ADJ operators?
ProQuest databases employ two different operators to apply adjacency to search terms:
- PRE or P/n
- NEAR or N/n
PRE - Will look for documents that contain one search term that appears within a specified number of words before a second term.
NEAR - Will look for documents that contain two search terms, in any order, within a specified number of words apart
The following table shows how HDAS translates ADJ/OADJ when searching on ProQuest databases
|HDAS Syntax||Translated ProQuest Syntax|
Do I need to use brackets in a long search?
If you are constructing a complicated search, using AND and OR in the search box, you may need to use brackets to ensure that the search retrieves the right results. This is because of the operator precedence used by the various providers.
If you are ambiguous in how you structure your query, then your search will fall back to the default order of precedence, potentially not generating the search you expect
If you want to search for articles which include depression and either cognitive behaviour therapy or CBT in the title, you should search for:
If you don’t include the brackets, you will retrieve a search for articles with either CBT in the title or both cognitive behaviour therapy and depression in the title.
What is a wild card?
A wildcard is a symbol that takes the place of one or more letters. In HDAS there are several wildcard symbols.
Right hand truncation is shown as an asterisk (*). You can put the wildcard at the end of your search term to search on all words that start with those letters. For example, depress* will find depressed, depressive and depression.
You can also specify the maximum number of characters you want to search for after the wildcard. For example, therap*4 will find therapy and therapist but not therapeutic.
When using the right hand truncation wildcard in Medline, PyscINFO or BNI, by default truncation is set to 5 characters. So a search for retin* would return retina but not retinopathy. This can be overridden by adding the number of characters you want to include after the asterisk. This is effective up to *9.
Optional wildcards are represented by the ? symbol.. The optional wild card can be used within or at the end of a search term to substitute for one or no characters. This wild card is useful for retrieving documents with British and American word variants. Example colo?r retrieves results that contain the words color or colour. You can use multiple wild cards in a single query word.
i.e. colo?r* would return (amongst others):
How do I apply a search limit?
If you are searching in just one database, you can apply any of the limits available in that database.
These can be applied either as you are searching or after you have completed a search. To apply a limit before you run a search, simply select the specific limits you wish to apply from the list. When you are happy, click search.
To apply limits to a combined search, then there are two methods, which vary depending on when in the process limits are to be added.
Adding limits when you're creating a combined row
If you want to add limits as you're creating a combined row, then this is achieved in the same way as applying limits:
- Create the rows you want to combine
- Select the rows to combine either using the checkboxes or by typing the command (OR or AND) into the search box
- Before you click combine, select the limit you wish to apply
- Click Combine
Your combined search is run with the selected limit included
Adding limits after you've created a combined row
To apply limits to a row which has already been combined, you'll need to create a new row which references the combined row. This is because you can't directly edit a combined row:
- Create a new search row which just includes the combined row number; this is achieved by typing the row number into the search box
- Select the limit you wish to apply and click search
Your new row includes the combined search limited by whichever limit you selected
How do I combine search terms?
Searches can be combined in two ways. You can use the checkboxes available above the strategy to manually select the rows you want to combine and the way in which you want to combine them. Alternatively you can enter the shorthand syntax to combine rows.
To combine using the site interface
Check the box next to the line numbers you want to combine, then check either the AND or OR button, and click Combine. If you combine your search terms using AND, you will retrieve results which include all the search terms. If you combine your search term using OR, you will retrieve results which include any of the search terms. You cannot combine a search in one database with a search in another database.
To combine using syntax
Combining searches using HDAS' syntax is very straight-forward. to combine rows, simply type ROW1 AND/OR ROW 2.
i.e. to combine rows 1 and 2 with an OR, simply type 1 OR 2.
The system automatically recognises that you've specified the syntax to combine rows, rather than searching for the numbers 1 or 2
How do I rerun my search in another database?
You can choose to re-run individual lines of a strategy, or each line of your search. To do so:
- Choose which lines you want to re-run
- Select the database you’d like to use
- Click Rerun selected
The system will then add the new lines to the bottom of your existing strategy
Can I reference searches using their line ID?
Yes. HDAS supports the use of a line number to reference the corresponding line of your query. So entering '1' in the search box will run the query that you'd entered as line one.
If you're referencing rows using their search ID, then to include fields and limits, you'll need to pick these from the user interface rather than entering the shorthand syntax. If you use the syntax, then the system interprets the numbers as the search you want to run.
Are there any other terms I should avoid?
Several of the databases have other reserved words (words they use in their syntax and therefore can't be searched outside of a phrase.
- USE - searches on OVID databases interpret USE as an indicator which database to use. using this term will return an error from the provider
- PRE - ProQuest use PRE to search for terms that appear within a specified number of words of one another (in the order entered)
- NEAR - ProQuest use NEAR to search for terms within a specified number of one another in any order
How do I use the thesaurus?
Each database has a thesaurus, which is an index of the controlled language available. To use the thesaurus, enter your search term, and click Thesaurus. HDAS will then show you terms which match your entered phrase. From here, you can select terms to add to your search, or explore further to identify related terms you may want to add to your search. From the thesaurus, you can also:
- Major a search term - If you select major, then the thesaurus term will limit results to those where the selected term is (one of) the key topics being discussed.
- Explode a search term - Selecting to explode a term will include that term as well as any child nodes in your search.
- View Scope Notes - A lot of records include scope notes, which give important contextual information about the term. These can include information about what the term refers to, any related terms or further background information.
- View subheadings - Subheadings are a way of further refining a search based around a thesaurus term.
You can also enter thesaurus terms directly into the search box. HDAS uses the following syntax for thesaurus terms:
|TERM/||Thesaurus terms are followed by a forward slash|
|*TERM/||Majored thesaurus terms are denoted by a *|
|exp TERM/||Exploded terms use exp before the term|
|exp *TERM/||If you major AND explode a term then combine both previously used pieces of syntax|
|"TERM & TERM"/||If you select a thesaurus term that includes punctuation or special characters such as brackets or ampersands then enclosing it in quotes ensures you get back the correct result|
What are the terms that appear at the top of the page?
As you're moving through the thesaurus, any terms you select are displayed above the thesaurus. This means that you can navigate to different areas of the tree without losing the selections you've made.
What is the difference between 'Search now' and 'Search as individual queries'?
when you've identified multiple thesaurus terms, you can add them into your search strategy in one of two ways.
Search now will include each of the thesaurus terms you've selected, combined with the operator you've chosen.
Search as individual queries will take each of the terms you've selected and create a separately numbered row in your search strategy.
Both options work with regular selection of a terms as well as exploded and majored terms. These two options mean that you can identify all the terms you want in the thesaurus before you run your search.
why do I sometimes get numbers on Scope Notes?
This is a result of the way the thesaurus providers supply us with information. When you first run a thesaurus search, HDAS is not told whether a term has a scope note (this is why all terms have the scope note link). Once you've accessed a scope note, then the system is able to fill in this information and can confirm how many scope notes a particular line has. We change the link to a number so that i ti is consistent with how we display broad, narrow and used for terms.
Viewing and saving results
How do I view my results?
To view your results, click the view results link for the search you want to view. From your strategy, you can immediately see which result set you are viewing. Your results are displayed in line below your strategy.
How do I save my strategy?
Every time you add search rows to a strategy, the system automatically saves your work. This ‘history’ is saved within the ‘My Search Strategies’ tab. These search strategies are available on a rolling one month basis from the time they were last accessed. To save your search strategy permanently, simply enter a name into the box labeled ‘Name this Search Strategy’.
How do I reorder search rows?
alongside each row in your search strategy, you'll see two triangles. If you click and hold these, you can move rows in your strategy to change the order. When you select a row, the bar will be coloured green. To move items, make sure that your cursor is over the rows themselves.
How do I filter my strategies?
If you’ve built up a long list of strategies, finding the one you want can be difficult. To filter the list, simply begin to type. The list will automatically filter to records that contain the text you’ve typed. In place filtering applies to the name of your strategy and the databases used.
How do I change the order of the results?
When you’ve selected an individual database, you can use all of the result sorting options that the provider offers, regardless of the number of results. By default, results are sorted by relevance. If you’ve selected multiple databases, then you’ll only be able to sort by the options which are common to each provider.
How do I see the abstract?
If an article has an abstract, you can view this inline, by clicking the view abstract link below the record. This will open the abstract inline. To view all abstracts, select Show Abstracts from above the result set. This will toggle all of the abstracts on and off.
What are saved results?
Saved results allow you to build a collection of individual results and then manipulate them in the same way you do for search strategies. Saved results replace the clipboard, but provide an advanced level of functionality. Rather than having a single global clipboard, you can now save results sets against each strategy. This allows you to save individual results from multiple databases.
The other benefit is that you can now save multiple sets of saved results, one for each strategy that you have created. Saved results show as an additional line at the bottom of your strategy. You can also access a list of all the saved results sets you’ve created and quickly jump to the list within the context of the strategy it belongs to. This makes it really simple for you to continue to add new records to that set.
When you're in saved results, you can sort results from multiple databases by title or publication date. You can also view upto 1000 records at a time.
This approach also allows you to work on multiple strategies for different recipients at the same time.
How do I delete a saved search or alert?
To delete a saved search go to My Strategies, check the relevant search and click Delete.
To delete a save alert go to My saved alerts, check the relevant search and click Delete Alert.
Deduplication in HDAS is much more active than previously. Now, instead of running deduplication only when you activate it, the process runs every time you add records to a saved result set. The system doesn't make any decisions about which records to delete, this is still a process you'll need to oversee. There is however the option to let HDAS make a bulk decision for you.
How do I deduplicate my results?
accessing deduplication is as simple as accessing your saved results. As soon as you view these, the system will tell you how many duplicate records it has identified and give you the option to view these in a way which makes removing superfluous records easy.
Using the deduplication feature
Once you've accessed your saved results, you'll see at the top of the results list a section which tells you whether your results set is free of duplicate entries, or how many duplicates have been identified. These duplicates are identified by comparing the titles of records.
Clicking the link "view only the x results with duplicate entries" will switch you to a two column view which allows you to compare the entries HDAS thinks are duplicates. At this point, you can either manually review the lists and make a decision about which entries you'd like to keep or you can use the 'Select only duplicates' button to have HDAS automatically select one of the duplicate entries to delete.
How does HDAS deal with duplicates?
HDAS identifies groups of duplicate records. In most instances, these are straight-forward one-to-one duplicates, i.e. record B is a duplicate of record A. Sometimes, the system identifies more than two records in a group, i.e. records B and C are duplicates of A.
Clicking 'Select only Duplicates' will select only those records which are exclusively duplicates. Deleting these will reduce the number of records shown as having duplicates.
This iterative approach allows you to control which records are deleted on a more granular level. If you want to override this, then you can select the additional records on the right before you delete to get a fully deduplicated record set.
In either case, no entries will be deleted until you click 'Delete selected' and confirm the deletion.
What does HDAS deduplicate records on?
HDAS currently uses several methods to determine if two records are duplicates of one another. The first is a simple comparison on PMIDs if they are available. If PMIDs are not available, then we use title. This method takes the title of each record and calculates the number of changes required to make them identical. This allows us to determine a percentage match for the documents. Anything which is over 90% similar is marked as a duplicate.
How do I combine my searches?
When you've created multiple search rows, you can combine these together to narrow or widen your search as appropriate. this can be done either by using shorthand syntax directly in the search box, or by using the controls on the website.
Combining with syntax
To combine with syntax, simply enter the row numbers you want to combine (along with the operator) into the search box, i.e. 1 AND 2. As soon as you add the operator, HDAS recognises that you want to combine searches and changes the search button accordingly.
Combining using the user interface
To combine searches using the site controls, tick the checkboxes of the rows you want to combine. When you do this, the combine control function will be activated. This allows you to choose how you want to combine, either with AND or OR. When you've made this choice, click combine and your request will be processed.
Are there any restrictions for combining rows?
There are several restrictions for combining rows, due to the way data is structured by providers. You'll be unable to combine rows if:
- They originate in different databases
- You've applied limits to one or more rows
- Your search was run on multiple databases
How do I export my results?
To export results from HDAS, click the export button located above your search strategies. This enables the export functionality. from here you can select:
- which search row you want to export
- the number of results you want to include
- the level of detail you want
- which format you require
- whether you want to download or email your export
What output formats can I choose?
You can output your results in the following formats:
- Microsoft Word (docx)
- Microsoft Excel (xlsx)
What fields are included in my export?
HDAS allows you to export three different levels of report. The following table shows the fields that are included in all three.
|Field Name||Export Size|
How do I download more than 500 results?
If you want to download more than 500 results, you can instruct HDAS which result you want to start your download at. To access this, simply set your download size to 500. HDAS will now present a secondary selection allowing you to choose:
Why can I only download 4000 records?
Unfortunately 4000 records is a limit imposed upon us by the database providers
How do I email my export?
To email your export, click the email results button. This will present you with an input for you to enter the email addresses you want the export to be sent to. You can also change the subject heading from the default. Click send and your email will be generated and sent
Can I send emails to more than one person at a time?
Yes. To do this just enter all of the emails into the text box. These can be comma, space or semi colon separated
Alerts in HDAS allow you to get timely updates about new content which matches a specific row from a search strategy you've created (or created for someone else). Alerts can be set to run at a number of frequency intervals, provide outputs in a number of formats and include differing levels of detail. You can also specify where the alert is sent, either to yourself or to a third party.
How do I set up an alert?
Setting up an alert in HDAS is a simple process, but there are several pre-requisites before you can do this. Firstly, you must save the strategy. Secondly, alerts can only be set up on search rows which are only run against a single database.
To create an alert, find the search row you want the alert to be run against in the search strategy table. When you've identified the row, you'll notice that there is a bell icon on the right hand side. This icon only appears on rows where creating an alert is applicable. Clicking the bell will open the alert options.
When creating an alert, there are several options you can change which will affect both the type and frequency of alert which is created:
- Frequency - Specify how often you want the alert to be fired. Either weekly, fortnightly or monthly
- Format - Choose the format of file you want the export to be sent in. Options include PDF, Word, Excel or RIS
- Type - Select whether you want full, medium or short. these correspond to the fields included in an export
- History - Here you can choose if you want the export to include the full search history or not.
- Alert name - Give your alert a name to make future identification easier.
- Alert email - Here you can enter an email address to select if the alert should be sent to yourself or to a third party. If you leave the field blank, the alert will default to the address registered to your OpenAthens account. If you need to send the alert to multiple users, then you can add more than one address into the box. These can be separated by either a comma, colon or space.
whether you send an alert to yourself or a 3rd party affects the type of alert sent. If you choose to send alerts to yourself, then we will include a link to the download on HDAS which will be generated at the point you access the link. If you elect to have an alert go to a third party, then we will generate the file and send this as an attachment, so users don't need to worry about having access to HDAS.
After you've completed these fields, clicking Save will store the alert on the system. The entire search row will become yellow to indicate that an alert has been created and the bell icon will change colour.
How do I know my alert has been set up correctly?
When you've created your alert, it is instantly sent to the email address you specified. This allows you to check that it is working straight away
You can also test an alert at any time by clicking the 'send test alert' button against each alert. this will fire the alert with the parameters for the current date
Syntax Help: Free-Text Searching
The HDAS syntax is given in the table below. In each paragraph, the equivalent in each native interface is given, along with a short explanation.
|OR||OR||cat OR mouse|
|AND||AND||cat AND mouse|
|NOT||NOT||cat NOT mouse|
|##||Multiple mandated wildcard||nurs##|
|?||Optional wildcard||colo?r||ProQuest do not offer the ability to replace 0-1 characters. Optional wildcards replace multiple characters|
|*n||Right-hand truncation||nurs*3||nurs*3 Not supported on EBSCO|
|ADJ||Proximity search (ordered)||mathematical ADJ model|
|ADJn||Proximity search (unordered)||mathematical ADJ3 model|
|OADJn||Wider proximity search (ordered)||mathematical OADJ3 model|
Due to the nature of how wildcards are implemented by the various database providers, there are some limitations to how wildcards behave. HDAS applies three main types of wildcard character:
- mandatory wildcard
- optional wildcard
- right-hand truncation
For each of these wildcard characters, HDAS translates to the equivalent symbol for the database you are searching. In some instances this may cause unintended results. This is because the native database providers interpret wildcards differently
Syntax Errors: Troubleshooting
xx is not a valid field for this database You've entered a field code which doesn't exist on the database you're searching. For each database, a list of field codes is shown in the 'fields' section. Note: because fields are standardised across databases, some codes may differ from those used on the providers native interface
field list error, missing field code You've ended your search with a comma. The system interprets that as missing a field code. You can either add the field code you missed, or remove the comma from the query.
missing '(', please close all brackets You've closed a bracket, but not opened it. The error will let you know where in your query the open bracket is missing
"missing ')', please close all brackets You've opened a bracket, but not closed it. The error will let you know where in your query the closed bracket is missing
special character. Please include your phrase within double quotes If you include special characters, these can confuse the way different providers interpret results, giving you an incorrect output. To fix this, simply add "double quotes" around your search. This applies to the thesaurus.
missing operator, expecting AND, OR, NOT, ADJ, OADJ it looks like you've missed an operator.
operator error, operators can only exist once between terms You've included two operators together, i.e. (cancer) AND OR (cells). Each operator should be surrounded by terms. To rectify, either remove one of the operators or add the missing term.
unfinished thesaurus term, please add a closing / You've tried to use a thesaurus term, but haven't included the forward slash to signify this to the system. Add / to the end of your term.
missing '\', please close all quotes You've opened a set of double quotes but haven't closed them so the system doesn't know where your phrase ends. The error will alert you to where we believe the closing quote mark should be.
$ is not a valid character, did you intend to use the * wildcard? The $ (dollar) symbol is not valid syntax in HDAS.
PubMed - Medline from PubMed 1946 to present
PubMed comprises over 25 million citations for biomedical literature from MEDLINE, life science journals, and online books. PubMed citations and abstracts include the fields of biomedicine and health, covering portions of the life sciences, behavioral sciences, chemical sciences, and bioengineering. PubMed also provides access to additional relevant web sites and links to the other NCBI molecular biology resources. PubMed is a free resource that is developed and maintained by the National Center for Biotechnology Information (NCBI), at the U.S. National Library of Medicine (NLM), located at the National Institutes of Health (NIH).
Importing strategies from the old HDAS
As part of the migration to the new HDAS platform, you'll be able to import strategies you've previously created going back to 2008.
How do I import my strategies?
When you log into the system, you'll see a new menu item in the navigation alongside saved results and alerts, titled 'Import'. Accessing this will allow you to view all of the strategies you've created, grouped together by year. Select a year and all of your strategies will be listed. When you've found the strategy you want to import, selecting it will build each line of that strategy in the new system.
Due to the differing structures of the database between both systems, there are some known issues you may encounter when importing search strategies. Where these errors occur, the system will flag the line in question and the built in error checker will show you where the problem occured.
potential issues that could occur
- Square brackets around subheadings - In old HDAS, searches with subheadings are in the following format: NEOPLASMS/PS [PS=parasitology]. This use of square brackets causes issues with limits (which are also identified by square brackets. To resolve this, the square brackets and their text has been removed. This means that where subheadings have been used, you'll need to remove the square brackets from the search, so that your subheading becomes NEOPLASMS/PS
- Date limit doesn't contain a hyphen - if you've applied a date range limit, then for this to be valid, you will need to add a hyphen between your start and end year.
- Combining across databasesIf you've created rows which search multiple databases, these will fail due to the fact new HDAS does not support cross database combining.
- Number usage - Some rows may give an error where numbers are used to reference a line (i.e. 1 AND 2). This issue is caused because of the way the information is stored in old HDAS which doesn't take into account where lines have been deleted. this means the system is unable to find the rows it expects and so defaults to running a search with the numbers as free text. To fix, this, you'll need to update the row so that they reference the correct rows in the new strategy.
Do I need to import everything?
No, we're planning on making the import functionality available for a prolonged period of time to allow you to import strategies as you need them. This also allows us to avoid re-running every strategy that was created in the old system at the same time, but also means you aren't under pressure to import everything in one session.
Additional Help Materials
In addition to this guide, there are a number of other tools which can help you to make the most of HDAS: